/ Thesaurus / U Synonyms of unthoughtfulness Find synonyms for: Noun1. unthoughtfulness, thoughtlessness, traitusage: the trait of not thinking carefully before actingWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: simian Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language