n. pl. (Anat.) The narrow passage from the mouth to the pharynx, situated between the soft palate and the base of the tongue; - called also the isthmus of the fauces. On either side of the passage two membranous folds, called the pillars of the fauces, enclose the tonsils. (Bot.) The throat of a calyx, corolla, etc.
- (Zool.) That portion of the interior of a spiral shell which can be seen by looking into the aperture.