/ Dictionary / Index A adenoid: Meaning and Definition of Find definitions for: ad•e•noid Pronunciation: (ad'n-oid"), [key] — n. Usually,an enlarged mass of lymphoid tissue in the upper pharynx, often obstructing breathing through the nasal passages. See diag. under —adj. of or pertaining to the lymph glands. of or pertaining to the adenoids. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: adenoid (Thesaurus) adenohypophysis adenoidal Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language