adj

• (anatomy, relational) Of or pertaining to the nose or to the nasion.
  "Reindeer are well suited to the taiga’s frigid winters. They can maintain a thermogradient between body core and the environment of up to 100 degrees, in part because of insulation provided by their fur, and in part because of counter-current vascular heat exchange systems in their legs and nasal passages."
• (phonetics) Having a sound imparted by means of the nose; and specifically, made by lowering the soft palate, in some cases with closure of the oral passage, the voice thus issuing (wholly or partially) through the nose, as in the consonants m, n, ng.
  "nasal vowel"
• (phonetics) Characterized by resonance in the nasal passage.
  "nasal utterance"
• (music) Sharp, penetrating.

noun

• (medicine, archaic) A medicine that operates through the nose; an errhine.
• (phonetics) Ellipsis of nasal consonant.
• (phonetics) Ellipsis of nasal vowel.
• (historical) The part of a helmet projecting to protect the nose; a nose guard.
  "The nasal continued in use until about 1140, when it was generally discarded, but isolated examples may be found in every succeeding century down to the seventeenth."