also gip, "to cheat, swindle," 1889, American English, traditionally derived from Gypsy (n.). Gyp/gip/jip is attested from 1794 as university slang for a servant that waited on students in their halls. This is said to have been especially a Cambridge word, and a story told there derived it from Greek gyps "vulture," in reference to thievish habits of the servants.
As a noun, "fraudulent action, a cheat," by 1914. Gypsy's abbreviated form Gip, Gyp is attested from 1840. Gypping or gipping was a term late 19c. among horse dealers for tricks such as painting the animal's gray hairs brown, puffing the gums, etc. Related: Gypped.