Cuss v.

Vulgar U.S. pronunciation or attenuation of CURSE.

1848.  Lowell, Biglow P., iv. Their masters can cuss ’em an’ kick ’em. Ibid., ix. I wish I may be cust.

1861.  Sat. Rev., 7 Dec., 583. This is why people like Major Pendennis go cussing up stairs and down stairs, as his valet described that hero doing.