/ Dictionary / Index A acanthoid: Meaning and Definition of Find definitions for: a•can•thoid Pronunciation: (u-kan'thoid), [key] — adj. spiny; spinous. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: acanthoid (Thesaurus) acanthodian acanthology Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language