/ Dictionary / Index A aciculum: Meaning and Definition of Find definitions for: a•cic•u•lum Pronunciation: (u-sik'yu-lum), [key] — pl. -lums, -la an acicula. one of the slender, sharp stylets embedded in the parapodia of certain annelid worms, as the polychaetes. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. aciculate acid Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language