/ Thesaurus / B Synonyms of boxcars Find synonyms for: Noun1. boxcars, twelve, 12, XII, dozenusage: (usually plural) an expression used when two dice are thrown and both come up showing six spotsNoun1. boxcars, twelve, 12, XII, dozenusage: a freight car with roof and sliding doors in the sidesWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language