Green’s Dictionary of Slang

(US) a rich, spoiled Jewish girl, also of a boy, i.e. prince; thus adj. jappy.

1969–70		Transatlantic Rev. XXXII–V 69: I’m married. To my Jap — my Jewish American Princess.
1981		Maledicta V:1+2 (Summer + Winter) 100: jap was quickly taken up by non-Jewish students, who sometimes plug in Prince to make the acronym do double duty.
1983		R. Price Breaks 157: Everyone else said, ‘this Jap.’ Fonseca’s guys said, ‘this Jewish chick.’.
1989		H. Rawson Dict. of Invective (1991) 217: JAP (Jap). An acronym for Jewish-American Princess (or Prince), as in The Official J.A.P. Handbook (Anna Sequoia, 1982).
1997		E. Little Another Day in Paradise 81: Fuckin’ broads, yenta, JAP, bitch. [Ibid.] 114: A gorgeous young JAP like me.
2002		(con. 1980s) i80s.com 🌐 JAP Jewish American Princess. Also used to describe a prissy Jewish girl who dresses preppy, spoiled and is a sexual tease.
2005		R. Cea No Lights, No Sirens 196: [T]he man who was boxing me in [...] being jerked off by the Jappy North Shore socialite in training.