/ Dictionary / Index U underpinning: Meaning and Definition of Find definitions for: un•der•pin•ning Pronunciation: (un'dur-pin"ing), [key] — n. a system of supports beneath a wall or the like. Often,a foundation or basis: to uncover the emotional underpinnings of an illness. underwear, esp. women's underwear. the legs. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: underpinning (Thesaurus) underpin underpitch vault Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language