Green’s Dictionary of Slang

1. informations.

1930		J. Lait Gangster Girl 43: I never was stopped becus somethin’ I went after was hard to get — women, rackets, dough, ins.
1967		F. Salas Tattoo the Wicked Cross (1981) 207: Tell me what come down [...] Gimme some ins, ma-han.
1981		G.V. Higgins Rat on Fire (1982) 76: He’s got the ins down there, though, which is why he’s working them.

2. interests.

1952

Lait & Mortimer USA Confidential 217: If anyone appealed to the courts or to the city council against the vested ins the local press wouldn’t even publish it.

3. influence(s).

1978

W. Diehl Sharky’s Machine 224: He’s got connections. He’s got the ins.

4. (US campus) money [money is an in n.].

1997–2000

Da Bomb 🌐 16: Ins: Money.