Green’s Dictionary of Slang

gyp v.

[gyp n.1 ]
(orig. US)

1. [late 19C+] (also gypsy, jip) to cheat, to deceive, to renege on one’s debts.

2. [1910s–40s] (also gip) to steal; to rob from.

3. [1920s–30s] to disappoint.

4. [1970s] to play truant from school.