(also + up) to make or become rounder or fatter

(also + up) to make (something) become rounder or fuller

She plumped the cushions

(also + out/up) to cause (somebody or something) to become fat or fatter

(also + out) to become fat or fatter

(usu + down/into) to drop or sink suddenly or heavily

Exhausted, she plumped down in the chair

to drop, throw, or place (something or oneself) suddenly or heavily

(+ for) to decide on something out of several choices or courses of action

I'll plump for beer rather than wine

to drop, throw, or place (something or oneself) suddenly or heavily

informal with a sudden or heavy drop

The toddler sat down plump on his bottom

dated without qualification; directly