wop, noun, often capitalized
offensive — used as an insulting and contemptuous term for a person of Italian birth or descent
Etymology
Italian dialect guappo swaggerer, tough, from Spanish guapo, probably from Middle French dialect vape, wape weak, insipid, from Latin vappa wine gone flat
If I'm not mistaken it was originally to describe Italian immigrants during whatever period of time (world war 1 maybe?) and it was a acronym for Without Papers. As in not having a visa.
I could be mistaken though, I read that once from one source so not really done any due diligence.