fight back fight·back uncommon verb 1. defend oneself Synonymsfight back 2. fight against or resist strongly “The senator said he would oppose the bill” “Don” Synonymsfightopposefight backfight downdefend Related words Word family oppositionopposerfightfighter Broader terms fight Narrower terms recalcitrateresistrepel WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.