I. darn² (also darned) adjective spoken informal

1. used to emphasize how bad, stupid, unfair etc someone or something is Synonym : damn:
The darn fool got lost on the way.

2. a darn sight better/harder etc a lot better, harder etc Synonym : damn:
He’d earn a darn sight more money there.
—darn,
— darned adverb:
It was a darned good movie.

[TahlilGaran] Dictionary of Contemporary English ▲

II. darned /dɑːnd $ dɑːrnd/ 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

[TahlilGaran] Dictionary of Contemporary English ▲