/ Dictionary / Index H hypothecium: Meaning and Definition of Find definitions for: hy•po•the•ci•um Pronunciation: (hī"pu-thē'shē-um, -sē-um), [key] — pl. -ci•a the layer of hyphal tissue directly beneath the hymenium of an apothecium. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. hypothecate hypothenar Related Content Daily Word Quiz: drowsy Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language