Meaning

noun a mechanical damper; absorbs energy of sudden impulses

noun the layer of air that supports a hovercraft or similar vehicle

noun a soft bag filled with air or a mass of padding such as feathers or foam rubber etc.

originFrom Middle English quysshyn, from later Old French coissin (modern coussin), from Vulgar Latin *coxīnus (“seat pad”), derived from Latin coxa (“hip, thigh”) (with the suffix possibly after Latin pulvīnus (“pillow”)), ultimately from Proto-Indo-European *koḱs- (“joint, limb”).

Etymology from Wiktionary, CC BY-SA 3.0