a bit of fluff Definition

fluff
noun

1. Small bits of soft woolly or downy material.
2. colloq
A mistake, eg in speaking or reading aloud.
3. colloq
A duffed stroke at golf, etc.

verb fluffed, fluffing

1. To shake or arrange it into a soft mass.

Form: fluff something out (usually)
Form: fluff something up
tr & intr
2. Said eg of an actor: to make a mistake in (their lines, etc); to bungle something.

Idiom: a bit of fluff

slang
A young woman, often used to refer to someone's girlfriend.
Example: Harry's bit of fluff

Etymology: 18c: from earlier flue a downy substance.