flappy

[ flap-ee ]
/ ˈflæp i /

adjective, flap·pi·er, flap·pi·est.

slack or loose, so as to flap readily.

Origin of flappy

1900–05; flap + -y1; probably re-formation and not continuous with obsolete flappy flabby
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

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