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2.
An intensely insane person with manic tendencies. Can also be defined as a person whose lack of sleep has driven them to insanity.

An extremist with a need for chaos.
"That guy just came at me, out of no where. What an insaniac!"

"I think Tim's been up for 5 days now. He's really turning into an insaniac"

"Dude, I'm going skydive-snowboarding tomorrow. I'm a f***ing insaniac!"
by BK Lounge October 24, 2008
 
1.
An insane maniac.

Alternatively, an insane insomniac.
Dude, you were an insaniac on the soccer pitch!

"I'm crazy tired." "Does that mean you're an insaniac?"
by Acelyn Dove October 06, 2011