1: a stroke with something broad :slap 2obsolete: something broad and flat used for striking 3: something that is broad, limber, or flat and usually thin and that hangs loose or projects freely: as a: a piece on a garment that hangs free b: a part of a book jacket that folds under the book's cover c: a piece of tissue partly severed from its place of origin for use in surgical grafting d: an extended part forming the closure (as of an envelope or carton) 4: the motion of something broad and limber (as a sail or wing) 5: a movable auxiliary airfoil usually attached to an airplane wing's trailing edge to increase lift or drag — see airplane illustration 6 a: a state of excitement or agitation :tizzy, uproarb: something (as an incident or remark) that generates an uproar 7: a consonant (as the sound \d\ in ladder and \t\ in latter) characterized by a single rapid contact of the tongue or lower lip against another point in the mouth —called also tap