- 1 fluff something (informal) to do something badly or to fail at something synonym bungle He completely fluffed an easy shot (= in sports). Most actors fluff their lines occasionally.
- 2fluff something (out/up) to shake or brush something so that it looks larger and/or softer The female sat on the eggs, fluffing out her feathers. Let me fluff up your pillows for you.
NAmE//flʌf//Verb Forms present simple I / you / we / they fluff
he / she / it fluffs
past simple fluffed
-ing form fluffing