Synonyms for Mouth (same or very similar meaning)
WordNet sense 1 (a spokesperson (as a lawyer)):
mouthpieceWordNet sense 2 (an impudent or insolent rejoinder):
backtalk, lip, sass, sassingWordNet sense 3 (the opening through which food is taken in and vocalizations emerge):
oral cavity, oral fissure, rima orisWordNet sense 4 (express in speech):
speak, talk, utter, verbalize, verbaliseFrom the ODE community, based on WordNetadd/edit