adjective

1. uttered by the mouth; spoken
2. of speech; using speech
3. of, involving, or administered through the mouth
4. of or having to do with sexual stimulation of the genitals by the mouth or tongue
5. Phonet. having mouth resonance only
6. Psychoanalysis
   1. designating or of the earliest stage of psychosexual development, in which interest centers around sucking, feeding, and biting
   2. designating or of such traits in the adult as friendliness, generosity, and optimism or aggressiveness and pessimism, regarded as unconscious psychic residues of that stage
7. Zool. on or of the same side as the mouth

Etymology: < L os (gen. oris), the mouth < IE base *ōus-, mouth, edge > Sans -ḥ, mouth, ON ōss, mouth of a stream

noun