1relating to the nose:the nasal passages a nasal spray
2 Phonetics (of a speech sound) pronounced by the breath resonating in the nose, e.g. m, n, ng, or French en, un. Compare with oral (sense 2 of the adjective). (of the voice or speech) produced or characterized by resonation in the nose as well as the mouth:a drawling nasal voice
2 historical a nosepiece on a helmet.