darnedest adj. + Add to list US //ˈdɑɹndɛst// UK //dˈɑːndəst// darnedest Humorous Synonyms Synonyms blameblamedblastedblesseddamndamneddarneddeucedgoddamgoddamn Idioms1 entry01do one's darnedestTo do one's utmost; to make every effort or to try every possible approach or way.