also Keltic, 1650s, in archaeology and history, "pertaining to the (ancient) Celts," from French Celtique or Latin Celticus "pertaining to the Celts" (see Celt). In reference to the language group including Irish, Gaelic, Welsh, Breton, etc., from 1707. Of modern peoples or their other qualities, by mid-19c. The Boston basketball team was founded 1946. Celtic twilight is from Yeats's name for his collection of adapted Irish folk tales (1893).
ancient, dim northern constellation, mid-15c., Cephe, from Latin Cepheus, from Greek Kepheus, name of a mythical king of Ethiopia, husband of Cassiopeia, father of Andromeda.
"watch-dog guardian of Hades," late 14c., Latinized form of Greek Kerberos, which is of unknown origin, according to Klein it is perhaps cognate with Sanskrit karbarah, sabalah "spotted, speckled;" Sabalah was the name of one of the two dogs of Yama. Usually represented with three heads.
ancient southern constellation, from Latin, from Greek kētos "whale; large fish; sea-monster," a word of unknown origin.