adj. (Anat.) (a) Secreting mucus or phlegm; as, the pituitary membrane, or the mucous membrane which lines the nasal cavities. (b) Of or pertaining to the pituitary body; as, the pituitary fossa. Pituitary body or gland (Anat.), a gland like body of unknown function, situated in the pituitary fossa, and connected with the infundibulum of the brain; the hypophysis. - Pituitary fossa (Anat.), the ephippium.