I. darn 2 BrE AmE ( also darned ) adjective spoken informal
1 . used to emphasize how bad, stupid, unfair etc someone or something is SYN damn :
The darn fool got lost on the way.
2 . a darn sight better/harder etc a lot better, harder etc SYN damn :
He’d earn a darn sight more money there.
—darn,
— darned adverb :
It was a darned good movie.
II. darned /dɑːnd $ dɑːrnd/ BrE AmE adjective spoken informal
1 . I’ll be darned! used when you are surprised about something:
Did they really? I’ll be darned!
2 . I’ll be darned if ... used to emphasize that you will not allow something to happen
3 . darned if I know used to emphasize that you do not know something