fluffy

the word 'fluffy' is a relatively modern english formation. its core, 'fluff', emerged in the late 18th century, likely as an onomatopoeic alteration of 'flue' (meaning down or nap) or influenced by 'puff', evoking the light, airy quality of soft fibres. the adjectival suffix '-y', of old english origin, is productively added to nouns to mean "abounding in" or "having the quality of". thus, 'fluffy' literally means "full of fluff" or "having the characteristics of fluff", which directly informs its modern meanings describing anything soft, light, and airy in texture, from animals and pillows to cakes and clouds.

Structure: fluff (soft light fibres) + y (adjective-forming suffix) fluff (origin uncertain, possibly imitative; noun meaning light down or nap) + y (old english -ig; suffix forming adjectives meaning "characterized by, full of").