Definition of: phoneme

(fō′nēm) noun
A class of acoustically similar sounds in a language, usually written with the same phonetic symbol, which differ non–relevantly as conditioned by environment; the smallest unit in the sound system of a language, functioning to distinguish one morpheme from another. The contrasting phonemes /t/ and /p/ distinguish the words tin and pin, whereas the varying pronunciations of t in tip, stop and pit are not recognized by speakers of English and are considered members of the one phoneme /t/. See ALLOPHONE. [<F phonème a sound <Gk. phōnēma <phōnē a voice, sound]