Yours, Etc.: Origins and Uses of 8 Sign-Offs
c.1300, from Old French coissin "seat cushion" (12c., Modern French coussin), probably a variant of Vulgar Latin *coxinum, from Latin coxa "hip, thigh," or from Latin culcita "mattress." Someone has counted more than 400 spellings of the plural of this word in Middle English wills and inventories. Also from the French word are Italian cuscino, Spanish cojin.
1730s, from cushion (n.). In the figurative sense, from 1863. Related: Cushioned; cushioning.
cushion cush·ion (kush'ən)
A padlike body part.