1. One of the external openings of the nose, which give passage to the air breathed and to secretions from the nose and eyes; one of the anterior nares.
In sperm whales, porpoises, and allied animals, there is only one nostril, which is situated on the top of the head and called a spiracle.
2. Perception; insight; acuteness. "Methinks a man Of your sagacity and clear nostril should Have made another choice." (B. Jonson)
Origin: OE. Nosethril, nosethirl, AS. Nospyrl; nos for nosu nose + pyrel opening, hole, from pyrel pierced, for pyrhel, fr. Purh through. See Nose, and Through, and cf. Thrill.
Source: Websters Dictionary
(01 Mar 1998)