if'n

Old-timey contraction meaning "if and when"

I'll call you tomorrow if'n I get my homework done.

if'n

a variation of the word if.

I can carry you over to the farm if'n ya want me to.

if'n

If. An unnecessary, improper contraction of "if" and an obsolete mystery word, commonly used in the South.

Danzig lyrics from "Tired of being alive": "Don't care, if'n you die..."
Dylan lyrics from "Don't think twice, it's all right":

"sit and wonder why, babe, if'n you don't know by now"