The Etymology of Feline
Feline reached English in the early 17th century from Late Latin felinus, the adjective form of feles, the Latin word for cat. The deeper origin of feles is a small puzzle of historical linguistics. Indo-European languages do not share a single inherited word for cat — Greek ailouros, Latin feles, English cat, German Katze, French chat, Russian koshka are all from different sources, which is unusual for a familiar animal. The reason is that the domestic cat (Felis catus, descended from the African wildcat Felis lybica) only spread into Europe relatively late, sometime in the first millennium BCE, from Egypt where it had been domesticated some four thousand years earlier. Each European language picked up its own word locally. Latin feles originally seems to have meant any small predator that hunted vermin — a marten, polecat, or weasel — and was extended to the new domestic cat when it arrived. Cat itself comes from a Late Latin cattus, a separate non-Indo-European loan probably from Berber or another North African language. So feline (Latinate) and cat (Late Latin loan) name the same animal by entirely different routes.