archiphoneme

noun

ar·chi·phoneme

¦ärkē,

-kə̇ + ¦-

plural -s

: a class of phonemes consisting usually of a pair sharing all distinctive features except one (as d and t share all distinctive features except that d is voiced and t is voiceless)

especially : a structurally descriptive category in which a sound may be placed when it occurs in a position where it may belong to any of two or more phonemes because of neutralization or suspension of the usual contrast between them (as German t in final position where it may correspond either to medial t or to medial d)