darnedest UK /ˈdɑːndɪst/US /ˈdɑɹnˌdɪst/adjective 1noun 1phrases 1 adjective1 •(euphemistic) Damnedest; most amazing, consternating, etc.The darnedest thing happened to me today – I saw a man who I know died ten years ago. noun1 •(US) Damnedest; one's best effort.I did my darnedest to stay awake. Phrases with darnedest do one's darnedestTo do one's utmost; to make every effort or to try every possible approach or way.