Derivation from "You" and "Hunk" or "Hunky". Referrring to the Eastern European / Bohemian ethnicity (Slovaks, Poles, Hungarians, Russo-Slavic, et al) of the majority of 19th and 20th Century immigrants to work in the steel mills and coal mines. Bohunk is also sometimes used to describe the mixed / general ethnicity. Millhunk refers to one who works or has worked in one of the steel mills or foundries in the Greater Pittsburgh area.
Bob K: Naw, goin' with Tuddy to have a few. Yunk - you should come aht too.