/ Dictionary / Index R rhizoid: Meaning and Definition of Find definitions for: rhi•zoid Pronunciation: (rī'zoid), [key] — adj. rootlike. —n. (in mosses, ferns, etc.) one of the rootlike filaments by which the plant is attached to the substratum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: rhizoid (Thesaurus) rhizogenic rhizome Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language