Etymology
Advertisement
Capricorn 

zodiac sign represented as a goat, or half-goat half-fish, late Old English, from Latin Capricornus, literally "horned like a goat," from caper (genitive capri) "goat" (see cab) + cornu "horn" (from PIE root *ker- (1) "horn; head"). A loan-translation of Greek Aigokherōs, the name of the constellation. Extended 1894 to persons born under the sign.

Related entries & more 
Advertisement
Gemini (n.)
zodiac constellation, late Old English, from Latin gemini (plural of adjective geminus) "twins" (see geminate). Formerly also spelled gemeny, gemony, jeminy, etc. The twins are Castor and Pollux in Latin, which also are the names of the two brightest stars in the constellation; for their Greek name see Dioscuri. Meaning "a person born under the sign of Gemini" is recorded from 1894. As an oath, from 1660s (also found in Dutch and German), perhaps a corruption of Jesu (compare jiminy).
Related entries & more 
Libra (n.)
zodiac constellation represented by a pair of scales, late Old English, from Latin libra "a balance, pair of scales," also "pound (unit of weight)," from Proto-Italic *leithra- "pound." De Vaan compares Greek litra "name of a Sicilian coin," which "was probably borrowed from an Italic language at the stage containing [-thr-]."

Not a separate constellation in ancient Greece, where it was khelae, "the claws" of adjacent Skorpios. Nativized in Old Norse as skala-merki. Meaning "person born under the sign of Libra" is from 1894. Related: Libral; Libran.
Related entries & more 
Ganymede 

Trojan youth taken by Zeus as his cup-bearer (and lover), from Greek Ganymedes, perhaps a non-Greek name, or from ganymai "I rejoice, am glad" (related to ganos "brightness; sheen; gladness, joy; pride") + medea (plural) "counsels, plans, cunning" (see Medea); taken in Greek folk-etymology to mean "delighting in genitals."

Used figuratively of serving-boys (c. 1600) and catamites (1590s). Associated with Aquarius in the zodiac. As the name of one of the four large satellites of Jupiter, proposed in Latin 1610s, but not widely used before 1847.

Related entries & more 
Aquarius 

faint constellation and 11th zodiac sign, late Old English, from Latin aquarius, literally "water carrier," properly an adjective, "pertaining to water" (see aquarium); a loan-translation of Greek Hydrokhoos "the water-pourer," the old Greek name of this constellation.

The Aquarians (1580s) were a former Christian sect; its adherents used water instead of wine at the Lord's Supper. Aquarian Age (alluded to from 1913) is an astrological epoch (based on precession of the equinoxes) supposed to have begun in the 20th century (though in one estimate, 1848), it would be characterized by the traits of this sign, usher in world peace and human brotherhood, and last approximately 2,160 years. The term and the concept probably got a boost in popular use from the rock song "Age of Aquarius" (1967) and when An Aquarian Exposition was used as the sub-title of the Woodstock Music & Art Fair (1969).

Related entries & more 
Advertisement
Taurus (n.)

zodiac constellation, late Old English, from Latin taurus "bull, bullock, steer," also the name of the constellation, from PIE *tau-ro- "bull" (source also of Greek tauros, Old Church Slavonic turu "bull, steer;" Lithuanian tauras "aurochs;" Old Prussian tauris "bison"); from PIE *tauro- "bull," from root *(s)taeu- "stout, standing, strong" (source also of Sanskrit sthura- "thick, compact," Avestan staora- "big cattle," Middle Persian stor "horse, draft animal," Gothic stiur "young bull," Old English steor); extended form of root *sta- "to stand, make or be firm."

Klein proposes a Semitic origin (compare Aramaic tora "ox, bull, steer," Hebrew shor, Arabic thor, Ethiopian sor). De Vaan writes: "The earlier history of the word is uncertain: there is no cognate in [Indo-Iranian] or Tocharian, whereas there are Semitic words for 'bull' which are conspicuously similar. Hence, it may have been an early loanword of the form *tauro- into the western IE languages." Meaning "person born under the sign of the bull" is recorded from 1901. The Taurid meteors (peaking Nov. 20) so called from 1878.

At midnight revels when the gossips met,
He was the theme of their eternal chat:
This ask'd what form great Jove would next devise,
And when his godship would again Taurise?
[William Somerville, "The Wife," 1727]
Related entries & more