Astrology Glossary
A comprehensive reference of essential astrology terms and definitions. Whether you are just learning to read your birth chart or deepening your astrological knowledge, this glossary has you covered.
A
Ascendant (Rising Sign)
The zodiac sign that was rising on the eastern horizon at the exact moment of your birth. The Ascendant, also called the Rising Sign, determines the cusp of your first house and strongly influences your outward personality, physical appearance, and the first impression you make on others. It is considered one of the three most important placements in a birth chart, alongside the Sun and Moon signs.
Aspect
The angular relationship between two planets in a birth chart, measured in degrees along the ecliptic. Aspects describe how planetary energies interact and influence each other. Major aspects include conjunctions (0 degrees), sextiles (60 degrees), squares (90 degrees), trines (120 degrees), and oppositions (180 degrees). Harmonious aspects like trines and sextiles indicate flowing energy, while challenging aspects like squares and oppositions indicate tension that drives growth.
B
Birth Chart (Natal Chart)
A map of the sky at the exact moment and location of your birth, showing the positions of the Sun, Moon, planets, and other celestial bodies relative to the zodiac signs and houses. The birth chart, also called a natal chart, serves as a cosmic blueprint of your personality, potential, challenges, and life themes. Interpreting a birth chart requires knowledge of signs, houses, planets, and aspects.
C
Cardinal Signs
The four zodiac signs that initiate each season: Aries (spring), Cancer (summer), Libra (autumn), and Capricorn (winter). Cardinal signs are natural leaders and initiators, known for their ability to start new projects, take decisive action, and drive change. They represent the dynamic, pioneering energy of each element.
Conjunction
An aspect formed when two planets are within approximately 0-8 degrees of each other in the same sign, blending their energies into a powerful, unified force. Conjunctions are the most intense aspect, amplifying the combined qualities of both planets. The effect can be positive or challenging depending on the planets involved.
Cusp
The dividing line between two zodiac signs or two houses in a birth chart. Being 'born on the cusp' means your birthday falls within a few days of the transition between two signs. While you technically belong to one sign, you may feel the influence of both. House cusps mark the beginning of each house and determine which sign rules that area of life.
D
Decan
Each zodiac sign is divided into three 10-degree segments called decans, each spanning approximately 10 days. Each decan is ruled by a different planet within the same element, adding nuance to the sign's expression. For example, the first decan of Aries is ruled by Mars, the second by the Sun, and the third by Jupiter, creating subtle differences among Aries natives born at different times.
Descendant
The zodiac sign on the cusp of the seventh house, directly opposite the Ascendant. The Descendant represents the qualities you seek in partners and close relationships. It describes your approach to partnerships, the type of person you are attracted to, and the dynamics you create in one-on-one relationships.
E
Element
One of four fundamental energies that categorize the zodiac signs: Fire (Aries, Leo, Sagittarius), Earth (Taurus, Virgo, Capricorn), Air (Gemini, Libra, Aquarius), and Water (Cancer, Scorpio, Pisces). Fire signs are passionate and action-oriented, Earth signs are practical and grounded, Air signs are intellectual and communicative, and Water signs are emotional and intuitive. Elements describe the basic temperament and approach to life of each sign.
F
Fixed Signs
The four zodiac signs that fall in the middle of each season: Taurus (spring), Leo (summer), Scorpio (autumn), and Aquarius (winter). Fixed signs are known for their determination, persistence, and resistance to change. They provide stability, follow through on what cardinal signs initiate, and possess remarkable endurance and willpower.
H
House
One of twelve sections of a birth chart, each representing a specific area of life experience. The houses are determined by the time and place of birth. The first house governs self and identity, the second governs finances and values, and so on through the twelfth house of the subconscious and spirituality. Planets placed in a particular house focus their energy on that life area.
I
Imum Coeli (IC)
The lowest point of the birth chart, located at the cusp of the fourth house. The IC represents your roots, home, family, private life, and emotional foundation. It describes your innermost self, childhood environment, and the sense of security and belonging you seek throughout life.
Intercepted Sign
A zodiac sign that is fully contained within a house without appearing on any house cusp. Intercepted signs indicate energies that may be harder to access or express naturally. The qualities of an intercepted sign often require conscious development and may manifest later in life as hidden strengths that emerge through personal growth work.
L
Lunar Nodes (North Node & South Node)
The mathematical points where the Moon's orbit crosses the ecliptic (the Sun's apparent path). The North Node represents your soul's growth direction, lessons to learn, and destiny in this lifetime. The South Node represents past-life skills, comfort zones, and patterns to release. The Nodes are always in opposite signs and are considered among the most important points in spiritual astrology.
M
Midheaven (MC)
The highest point of the birth chart, located at the cusp of the tenth house. The Midheaven represents your public image, career aspirations, reputation, and life direction. It describes how the world sees you professionally and the legacy you aim to create. The sign on your Midheaven reveals your approach to career and public life.
Modality
One of three qualities that describe how zodiac signs express their energy: Cardinal (initiating), Fixed (sustaining), or Mutable (adapting). Each modality contains four signs, one from each element. Cardinal signs start things, Fixed signs maintain them, and Mutable signs transform and adapt them. Understanding modality helps explain the dynamic nature of each sign.
Moon Sign
The zodiac sign the Moon was in at the time of your birth. Your Moon sign governs your emotional nature, instinctive reactions, inner world, and subconscious patterns. While your Sun sign represents your conscious identity, your Moon sign reveals how you process feelings, what makes you feel secure, and your deepest emotional needs.
Mutable Signs
The four zodiac signs that conclude each season: Gemini (spring), Virgo (summer), Sagittarius (autumn), and Pisces (winter). Mutable signs are adaptable, flexible, and skilled at navigating change and transition. They are the communicators and synthesizers of the zodiac, able to adjust their approach based on circumstances.
N
Natal
Relating to the time of birth. In astrology, 'natal' refers to the positions of celestial bodies at the exact moment someone was born. A natal chart is synonymous with a birth chart. Natal planets represent the fixed, lifelong energies and themes in a person's life, as opposed to transiting planets which show current cosmic influences.
O
Opposition
An aspect formed when two planets are approximately 180 degrees apart, placing them in opposite signs of the zodiac. Oppositions create tension, polarity, and the need for balance between two competing energies. While challenging, they also offer the potential for great awareness and integration when both sides are honored.
P
Progressed Chart
A technique that symbolically advances the birth chart forward in time, with each day after birth representing one year of life. Progressed charts reveal the evolving themes, inner development, and shifting priorities of a person's life over time. A progressed Sun changing signs, for example, marks a significant shift in identity and life direction.
R
Retrograde
The apparent backward motion of a planet as observed from Earth. Planets do not actually move backward, but their orbital relationship to Earth creates this visual illusion. In astrology, retrograde periods are times of review, reflection, and revisiting themes associated with the retrograde planet. Mercury retrograde is the most well-known, associated with communication mishaps, travel delays, and technological glitches.
Return
When a transiting planet returns to the exact position it occupied in your birth chart. The most well-known is the Saturn Return, which occurs approximately every 29.5 years and marks major life transitions and maturation milestones. Solar returns happen annually on or near your birthday and are used to forecast themes for the coming year.
Ruling Planet
Each zodiac sign has a planetary ruler that governs its core energy and expression. For example, Mars rules Aries, Venus rules Taurus and Libra, and Mercury rules Gemini and Virgo. The ruling planet's position in a birth chart adds depth to how that sign's energy manifests in the individual's life. Understanding planetary rulership is key to chart interpretation.
S
Sextile
A harmonious aspect formed when two planets are approximately 60 degrees apart. Sextiles indicate opportunities, talents, and areas where energy flows with ease when activated. Unlike trines, which flow automatically, sextiles require conscious effort to unlock their potential. They represent cooperative energies that complement each other.
Square
A challenging aspect formed when two planets are approximately 90 degrees apart. Squares create internal tension, conflict, and friction that ultimately drives growth, motivation, and achievement. They represent areas of life where you face obstacles that push you to develop strength and resilience. Squares are considered the most dynamic and growth-producing aspects.
Stellium
A cluster of three or more planets in the same zodiac sign or house in a birth chart. A stellium concentrates a tremendous amount of energy in one area of life, making the themes of that sign or house extremely prominent in the person's experience. People with stelliums often have intensely focused personalities and life experiences.
Sun Sign
The zodiac sign the Sun was in at the time of your birth, and the most commonly known astrological placement. Your Sun sign represents your core identity, ego, life purpose, and conscious self. It describes the fundamental energy you express and the path of self-realization you walk throughout your life. When people ask 'What is your sign?' they are referring to your Sun sign.
Synastry
The astrological technique of comparing two birth charts to assess relationship compatibility and dynamics. Synastry examines how one person's planets interact with another's, revealing areas of harmony, attraction, tension, and growth potential in the relationship. It is widely used in romantic compatibility readings but applies to any relationship.
T
Transit
The current movement of a planet through the zodiac and its relationship to the positions of planets in your birth chart. Transits describe the cosmic weather affecting your life at any given time. When a transiting planet forms an aspect to a natal planet, it activates themes and events related to both planets and the houses they occupy.
Trine
The most harmonious aspect, formed when two planets are approximately 120 degrees apart, usually in signs of the same element. Trines indicate natural talents, ease, and areas of life where energy flows effortlessly. While highly beneficial, trines can sometimes indicate areas where you take gifts for granted due to their effortless nature.
V
Void of Course Moon
A period when the Moon has made its last major aspect to another planet before entering a new zodiac sign. During a Void of Course Moon, which can last from a few minutes to over a day, it is traditionally considered an unfavorable time to start new projects, sign contracts, or make important decisions, as outcomes may not unfold as expected.
Deepen Your Understanding
Learning astrological vocabulary is the first step toward reading and interpreting birth charts with confidence. Once you are familiar with the terms above, try generating your own free birth chart and identifying the signs, houses, and aspects in your personal chart. You can also explore our zodiac sign profiles for in-depth personality analysis based on your Sun, Moon, and Rising signs.