Green’s Dictionary of Slang

noogie n.

[? corruption of SE knuckle]

(US) the act of rubbing one’s knuckles hard across one’s victim’s skull; also used on other parts of the body.

[US]Wash. Post 31 May B1: [heading] Don’t Get Outta Here, Bill Murray; The ‘Saturday Night’ Whackos, Wailing for Freddie, With Noogies.
[US]S. King Christine 193: I started to poke my fingers at his sides [...] screaming ‘Side-noogies! Look out, Arnie, I got side-noogies onya!’.
[US]J. Lethem Fortress of Solitude 163: He kneaded and pinched, gave her spine a noogie.