/ Dictionary / Index E ectotherm: Meaning and Definition of Find definitions for: ec•to•therm Pronunciation: (ek'tu-thûrm"), [key] — n. Zool. a cold-blooded animal. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ectotherm (Thesaurus) ectostosis ectotrophic Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language