An object that's soft and fluffy is called fluff. This can also refer to small balls of loose hair, especially from animals.
When we use the word "fluff," it usually means something light and airy. We might talk about fluffing up a pillow or blanket to make it softer and more comfortable. You could even ask someone to give you a nice fluff on your hair after they brush it. Some people also use the word when describing cat or dog fur – like, "I just brushed my cat and now it's all fluffy." When we're talking about something that's being made soft and light, like fabric or hair, "fluff" is often what comes to mind.
How common is "fluff"?
Word fluff is considered rare in modern English. It appears most frequently in fiction texts and less often in other writings.
Definitions
noun
Anything light, soft or fuzzy, especially fur, hair, feathers.
Anything inconsequential or superficial.
Example: That article was basically a bunch of fluff. It didn't say anything substantive.
(informal) A lapse or mistake, especially a mistake in an actor's lines.
(informal, slang) A cloth diaper.
(New England) Marshmallow creme.
Example: That New England-style salami and fluff sandwich sure hit the spot!
(LGBTQ) A passive partner in a lesbian relationship.
(Australia, New Zealand, Canada, euphemistic) A fart.
(fandom slang) Fan fiction, or part of a fan fiction, which is sweet and feel-good in tone, usually involving romance.
Example: And when something triggers, I can close the window and go read fluff for hours until I calm down.
(UK, roleplaying games) A form of roleplaying which is inconsequential and not related to the plot; often used in the context of (but not limited to) filling time.
(UK, slang, obsolete) Short change deliberately given by a railway clerk, to keep back money for himself.