A jackass who has the added advantage of being a maniac.
example 1:
J-Dev:" That guy is driving like a stupid Jackmaniac!!"
example 2:
Sruti" Who is submitting so many words to the UD"
J-Dev:" Its some random Jackmaniac!"
a person hugely obsessed with Hugh Jackman
Sam: Daniel's mum is a right milf
Toby: I wouldn't go near her, she's a jackmaniac