Flap (definition)

A flap is a sound made using extremely quick contact, usually with the tip of the tongue ''flapping'' against a place of articulation. In English this is generally against the alveolar ridge.The flap is an allophone of [t] and [d] , as in butter or ladder. A flap is transcribed in IPA as [ɾ].

References

Matthews, P. H. The Concise Oxford Dictionary of Linguistics. Oxford: Oxford University Press, 1997.