/ Dictionary / Index H hydroid: Meaning and Definition of Find definitions for: hy•droid Pronunciation: (hī'droid), [key] — adj. noting or pertaining to that form of hydrozoan that is asexual and grows into branching colonies by budding. —n. the phase of a hydrozoan coelenterate that consists of polyp forms usually growing as an attached colony. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: hydroid (Thesaurus) hydrography hydrokinetic Related Content Daily Word Quiz: inutiae Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language