| Gemini (n. pl.) A constellation of the zodiac, containing the two bright stars Castor and Pollux; also, the third sign of the zodiac, which the sun enters about May 20th. Thesaurus Entries ATDA, ATS, Alouette, Anna, Apollo, Ariel, Atlas-Score, Biosatellite, Castor and Pollux, Comsat, Cosmos, Courier, Diapason, Discoverer, ERS, Early Bird, Echo, Elektron, Explorer, GATV, Injun, Intelsat, Lofti, Luna, Lunar Orbiter, Lunik, Mariner, Mars probes, Mercury, Midas, Nimbus, OAO, OGO, OSO, Pageos, Pegasus, Pioneer, Proton, Ranger, Relay, Samos, San Marco, Secor, Siamese twins, Sputnik, Surveyor, Syncom, Telstar, Transit, Tweedledum and Tweedledee, Twin Stars, Vanguard, Viking, Voskhod, WRESAT, Zond, artificial satellites, exact mates, fraternal twins, identical twins, pair of twins, spacecraft, twins |