Green’s Dictionary of Slang

a crazy person, an obsessive, an eccentric.

1900		Atlantic Monthly LXXXVI 108/2: ‘Meschugener,’ leered the banker. ‘He cannot see you,’ is the way the kinder clerk translated the message to Moses.
1941		A. Kober My Dear Bella 78: I know where she is, that meshugineh?
1958		(con. 1950) E. Frankel Band of Brothers 216: Pat heard Firesten calling. ‘You mischigunahs! Get back!’.
1961		T.I. Rubin In the Life 12: Ape, you know: for the nut wagon, psycho, mishuga.
1964		J. Charyn Once upon a Droshky 107: He runs like a meshuggina towards Delancey Street.
1965		R.L. Pike Mute Witness (1997) 150: ‘Meshuga,’ Doc Freeman muttered.
1967		L. Bruce Essential Lenny Bruce 52: You like to tell me that story, you meschugenah.
1970		T. Southern Blue Movie (1974) 37: Sid grimaced in pain. ‘No, mishugenah, the country for Chrissake! Lichtenstein’.
1975		A. Goldman Lenny Bruce 23: Is he crazy, this meshugana?
1986		C. Stroud Close Pursuit (1988) 158: You got the kid’s meshugana or whatever.
1990		S. Morgan Homeboy 294: You want to take the word of a shiksa, a prosecution witness and a certified meshuga, against mine.
1996		H. Roth From Bondage 391: Mishugeneh crazy; a crazy person.
2000		Indep. on Sun. Culture 2 Apr. 1: Big up to the meshugener massive.
2002		Juha ‘Polari’ 🎵 on Polari [album] Beach in the screech. Alamo jo! / This dizzy hoofer gonna dowry jeebo. / Varda me fatcha, meshigner bona. / Savvy you gettin fericadooza.