/ Thesaurus / Y Synonyms of youthfully Find synonyms for: Adverb1. youthfullyusage: in a youthful manner; "he is still youthfully enthusiastic"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: ontiguous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language