Green’s Dictionary of Slang

wiff n.1

(US) a wife.

[US]T.A. Dorgan Indoor Sports 17 Nov. [synd. cartoon] I’ll bet it’s old McKenna explaining to his wiff why he wasn’t home last night.
[US]Wood & Goddard Dict. Amer. Sl. 59: wiff. The wife, the missus, the better two-thirds.