Definition from Wiktionary, the free dictionary
Alteration of damn it
- (profane) Used to express anger, irritation, contempt, or disappointment.
- See also Wikisaurus:dammit
expression of anger or disappointment
dammit (plural dammits)
- The saying of the interjection, used as a general measure of anything.
2006, Dewey Lambdin, A King's Trade, pages 294:
- Get us about, quick as dammit! Clew up tops'ls, there!