[1] The Merriam-Webster dictionary states wop's first known use was in the United States in 1908, and that it originates from the Southern Italian dialectal term guappo, roughly meaning "dandy", or "swaggerer", derived from the Spanish term guapo, meaning "good-looking", "dandy", from Latin vappa for "sour wine", also "worthless fellow".
[5][6] As word-final vowels in Southern Italian varieties are often realized as /ə/, guappo would often sound closer to wahpp to anglophones.
[6] The word eventually became associated with members of the Camorra and has often been used in the Naples area as a friendly or humorous term of address among men.
[7] The word likely transformed into the slur "wop" following the arrival of poor Italian immigrants into the United States.
[10] Another backronym is that wop stands for "working on pavement", based on a stereotype that Italian immigrants and Italian-American men typically do manual labor such as road-building.