"distinctive sound or group of sounds," 1889, from French phonème, from Greek phonema "a sound made, voice," from phonein "to sound or speak," from phone "sound, voice," from PIE root *bha- (2) "speak" (see fame (n.)).
phoneme pho·neme (fō'nēm')
n.
The smallest phonetic unit in a language that is capable of conveying a distinction in meaning, as the m of mat and the b of bat in English.