/ Dictionary / Index E ectomorphic: Meaning and Definition of Find definitions for: ec•to•mor•phic Pronunciation: (ek"tu-môr'fik), [key] — adj. having a thin body build, roughly characterized by the relative prominence of structures developed from the embryonic ectoderm (contrasted with endomorphic, mesomorphic). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ectomorphic (Thesaurus) ectomorph -ectomy Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language