/ Dictionary / Index C calico clam: Meaning and Definition of Find definitions for: cal'ico clam" Pronunciation: [key] any marine bivalve mollusk of the genus Macrocallista, esp. M. nimbosa, having a smooth, thick, rounded shell marked with violet-brown or lilac spots or streaks. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. calico cat calico crab 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