Wop is an American English pejorative ethnic slur for an Italian. It is derived from the Neapolitan word "guappo" (often pronounced simply as "guap'" in the regional dialect), meaning a person who flaunts an overbearingly cocky and swaggering attitude.
In the past, it also could refer to someone following the guapparia, meaning bravery, i.e., the ancient honour code of...