Darn

·noun A place mended by darning.

II. Darn ·vt A colloquial euphemism for Damn.

III. Darn ·vt To mend as a rent or hole, with interlacing stitches of yarn or thread by means of a needle; to sew together with yarn or thread.

darn
An expletive in very general use among the vulgar, instead of damn. Now let me see, that isn't all;...

Dictionary of American Words And Phrases by John Russell Bartlett.