/ Thesaurus / S Synonyms of serious mindedness Find synonyms for: Noun1. seriousness, earnestness, serious-mindedness, sincerity, traitusage: the trait of being serious; "a lack of solemnity is not necessarily a lack of seriousness"- Robert RiceWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: languid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language