/ Thesaurus / C Synonyms of crank letter Find synonyms for: Noun1. crank letter, letter, missiveusage: a hostile (usually anonymous) letterWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: knead Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language