/ Dictionary / Index A armpit: Meaning and Definition of Find definitions for: arm•pit Pronunciation: (ärm'pit"), [key] — n. the hollow under the arm at the shoulder; axilla. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: armpit (Thesaurus) armpatch armrest Related Content Daily Word Quiz: abstain Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language