Meaning of “flap” - Learner’s Dictionary

flap

noun uk us /flæp/
CLOTH [ C ]

a piece of cloth or material fixed along one edge to cover or close an opening

EXCITEMENT [ C, U ] informal

the feeling of being worried or excited, or a situation that causes someone to feel this way:

The President's remarks caused a huge flap.

(Definition of “flap noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)