A phoneme is the smallest unit of sound which is significant in a language.
[technical]
phoneme in British English
(ˈfəʊniːm)
noun
linguistics
one of the set of speech sounds in any given language that serve to distinguish one word from another. A phoneme may consist of several phonetically distinct articulations, which are regarded as identical by native speakers, since one articulation may be substituted for another without any change of meaning. Thus /p/ and /b/ are separate phonemes in English because they distinguish such words as pet and bet, whereas the light and dark /l/ sounds in little are not separate phonemes since they may be transposed without changing meaning
Word origin
C20: via French from Greek phōnēma sound, speech
phoneme in American English
(ˈfoʊˌnim)
noun
Linguistics
a set of phonetically similar but slightly differing sounds in a language that are heard as the same sound by native speakers and are represented in phonemic transcription by the same symbol
in English, the phoneme /p/ includes the phonetically differentiated sounds represented by p in “pin,” “spin,” and “tip”
see also segmental phonemes, suprasegmental phonemes
Word origin
Fr phonème < Gr phōnēma, a sound < phōnein, to sound < phōnē, a voice: see phono-