/ Thesaurus / A Synonyms of assiduousness Find synonyms for: Noun1. assiduity, assiduousness, concentration, diligence, industriousness, industryusage: great and constant diligence and attentionWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: illegible Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language