AFFLICTED: Unfavorable planetary aspect: Squares, Oppositions and Quincunxes.
AIR SIGNS: Signs possessing the qualities of the element Air: intellect, thought process etc. The Air signs are Gemini, Libra and Aquarius.
ANERETIC DEGREE: The final degree of a sign (29th). 
ANGLES: The lines of the chart wheel which lie at 0 degrees (Ascendant), 90 degrees (I.C.), 180 degrees (Descendent), and 270 degrees (M.C.). These major points represent Cardinal Qualities.
AQUARIAN AGE: 2000 year period influenced by the qualities of Aquarius starting approximately at the new millennium.
ARC: An angular measurement between two celestial planets or points. Any part of a circle, measured around it’s circumference.
ASCENDANT: The Rising Sign. The degree at which the Zodiac rests over the horizon of the birthplace at the time of birth. The Ascendant represents the persona and image to the world.
ASPECT: The angular distance, calculated in specific number of degrees of the chart wheel, between two celestial points or planets. It shows the nature of the relationship between planets.

BIRTHCHART: A diagram showing the exact positioning of the planets in the signs at the moment of birth.

COMBUST: When a planet is very near the Sun in the birth chart. It is theorized that the planet loses some of its force.
CARDINAL SIGNS: Aries, Cancer, Libra and Capricorn. 
COMPOSITE CHART: Two individual charts which are merged to form one. It shows the relationship between two individuals.
CONFIGURATION: An Aspect which has three or more planets.
CONJUNCTION: Two or more planets sitting next to each other. A conjunction gives great strength to the energies of the interacting planets.
CUSP: A line dividing the twelve houses. The midway point between two signs.
CYCLE: The time it takes a planet or point to make one complete revolution in the heavens.

DECANATE: The division of each sign into three equal parts of 10 degrees each.
DECLINATION: The distance of a planet north or south of the celestial equator
DEGREE: 1/360 of a circle.
DESCENDANT: The opposite point from the Ascendant: cusp of the 7th house.

EARTH SIGNS: Signs belonging to the element Earth (practical etc.). Taurus, Virgo, Capricorn.
ELEMENTS: Four-fold division of the Zodiac: Fire, Earth, Air, and Water. Signs of the same element share qualities of that element.
EPHEMERIS: Astrological almanac listing Zodiacal positions of the planets and other Astronomical data.
EQUATOR: The imaginary line drawn around the Earth, dividing it into the northern and southern hemispheres. When this line is extended into space, it is called the celestial equator.
EQUINOX: A time of equal day and equal night occurring twice a year at the beginning of Spring and Autumn.

FEMININE SIGNS: The Earth and Water signs. Feminine signs are referred to as negative and indicate passive and receptive energy.
FIRE SIGNS: Aries, Leo, and Sagittarius. Signs with the qualities of the element of Fire 
FIXED SIGNS: Taurus, Leo, Scorpio and Aquarius.

GEOCENTRIC: The convention that the Earth, rather than the Sun is at the center of the Solar System.
GRAND CROSS: Configuration in which four planets form mutual squares. It creates a lot of tension.
GRAND TRINE: When three planets meet each other to form a triangle. This is a harmonious configuration.
GREAT YEAR: The period when the pole makes a complete circle.

HARD ASPECT: Squares, oppositions and quincunxes. 
HOUSES: The celestial sphere as a 360 degree circle is divided into twelve sections called houses. They are numbered counterclockwise from the Ascendant (9:00 position). Each house represents certain aspects of life.

Jupiter: The king of the gods, a planet symbolizing matters to do with the law, religion, authority, the higher mind and so on. Ruler of Sagittarius and Pisces. Exalted in Cancer. 
Jyotish: Indian (Vedic) astrology. This is based on the sidereal zodiac, as opposed to the tropical zodiac favored by most contemporary Western Astrology.

Key Words: Words that encapsulate the meaning of an astrological factor. 
Ketu: Name for the Dragon’s Tail, in Indian Astrology.

Latitude (Celestial): Measurement of distance of any planet or star north or south of the ecliptic. The Sun never has any latitude.
Latitude (Terrestrial): Degree of distance of any place north or south of the Earth’s equator.
Leo: This regal sign is the fifth sign of the zodiac. Ruled by the Sun. The exaltation of Pluto. Leo’s symbol is the lion.
Libra: The seventh sign of the zodiac, Libra is the sign most concerned with relationships. Cardinal and Airy. Ruled by Venus. The exaltation of Saturn. Libra’s symbol is the scales, or balance
Lights: Sun and Moon.
Logarithms: Tables by which when a planet’s motion is known its position at a given time may be readily calculated.

Long Ascension 
Signs of long ascension take longer to ascend than others. Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius. Long and short ascension are reversed in the southern hemisphere.
Longitude (Celestial): Measurement along the ecliptic in terms of signs and degrees from the point of the vernal equinox (0° Aries). The longitude of a planet in the 126th degree of the zodiac is 6° Leo.
Longitude (Terrestrial): Distance in degrees, minutes and seconds of any place east or west of Greenwich, England. 
Luna: The Moon. More about the Moon .
Lunar Mansions: 27 traditional sectors (nakshatras) of the zodiac, where the Moon spends her time on a day by day basis. Each mansion, of 13° 20′ duration, has a specific influence, especially if Moon, Sun, Ascendant, or Ruling Planet are placed there. This system is used today in Indian (Vedic) astrology. 
Lunar Node: See Nodes
Lunation: A lunar period, measured from one place in the zodiac until the Moon’s return thereto. For example, the time taken by the Moon from one conjunction with the Sun until the next, 29 days, 12 hours, 44 minutes and 3 seconds, is called a syndical lunation. Lunation is also used to describe different aspects of the Moon to the Sun, thus accounting for her phases. The New Moon is also called a Lunation. A chart made for the moment the Moon conjoins the Sun is called a Lunation Chart.

MASCULINE SIGNS: Aries, Gemini, Leo, Libra, Sagittarius and Aquarius. Masculine signs are assertive and self-assured.
MERIDIAN: The Meridian at Greenwich. The point from which time and space is measured. It divides longitude into east and west.
MIDPOINTS: The midpoint between two planets or angles and sometimes house cusps.
MUTABLE SIGNS: Gemini, Virgo, Sagittarius and Pisces.

NATAL: Birth. The natal chart refers to a chart for the time of birth.
NODES: The north and south nodes of the moon are those points on the ecliptic where the moon crosses it going either north or south.

OPPOSITION: An opposition is when planets are exactly opposite each other in the chart wheel. Oppositions create stress.
POLARITY: Opposite signs effect each other: each sign has a relationship with its partner across the Zodiac.
PROGRESSION: A method of advancing the planets and points of a natal chart to a particular time after birth.

QUALITIES: Cardinal, Fixed, Mutable.

RETROGRADE: When a planet appears to be traveling backwards from Earth’s perspective. The energy of a retrograde planet is less assertive.
RULERSHIP: Different signs are “ruled” by different planets and their influences can be affected by this fact.

SIDEREAL TIME: Time reckoned by the stars rather than by the Sun.
SOLSTICE: When the Sun reaches its maximum declination. This occurs twice a year, at the beginning of Summer and Winter.
STELLIUM: A group of planets gathered in one area of the Zodiac; sometimes, a multiple conjunction.
SUN-SIGN ASTROLOGY: As seen in newspaper Astrology columns, predictions for the day, month or year ahead on the basis of Solar Charts.
SYNASTRY: Comparing natal charts to find strengths and weaknesses in the area of compatibility.

TRANSIT: A planet’s movement through a sign or house.

Under the Sun’s Beams: Within 17 degrees of the Sun. Any planet here is weakened, though more so if combust (within 8 degrees 30 minutes). Not so important in natal astrology.
Uranus: Formerly known as Herschel, after its discoverer, this planet was not discovered until 1781. It has been deemed to rule Aquarius. It stands for unexpected disruptions and sudden catastrophes. Esoterically, it calls forth the genius in the character of the native.

Water Element: One of the four astrological elements. A feminine element, it stands for emotion, feeling, and matters to do with intuition and so on. The other elements are Fire, Air and Earth.
Water Signs: Cancer (cardinal), Scorpio (fixed), Pisces (mutable)
ZODIAC: From the Greek ‘zodiakos’, meaning ‘circle of animals’. A band in the heavens divided