noun

nincompoop

NING-kum-poop/ˈnɪŋkəmpuːp/

A foolish or silly person.

The nincompoop saws through the branch supporting her own seat.

A foolish gardener sits on the outer end of a low tree branch while sawing through that same branch between herself and the trunk, visibly undermining her own seat.

Etymology

The origin is unresolved, but early definitions already describe a fool or a silly, excessively devoted husband. The general insult preserves that early meaning of foolishness.

In context

BBC America0:25

I didn't know that she'd done this and I turned on Netflix like she'd gone to bed and I turned it on and there's my face but she called it nincompoop like

Claire Foy is Not a Nincompoop | The Graham Norton Show | BBC America

More examples

Only a nincompoop would leave ice cream in the car.
He calls himself a nincompoop after sending the wrong file.
Those nincompoops keep arguing instead of reading the instructions.

Forms

nincompoop · nincompoops

Similar words

fool: Broader and less playful; can emphasize seriously poor judgment.
idiot: Usually harsher and more directly insulting about someone's intelligence.