English word tails comes from English tailcoat

Detailed word origin of tails

Dictionary entry	Language	Definition
tailcoat	English (eng)	A formal evening jacket with an extended back panel; a dress coat.. Any coat with similar tails.
tails	English (eng)	(mining) tailings; waste. (slang) short for .. The side of a coin that doesn't bear the picture of the head of state or similar.