Green’s Dictionary of Slang

(US, esp. US Ital.) a stupid or unpleasant person.

1968		K. Brasselle Cannibals 64: Why do you keep those jadrools around when you know goddam well they have nothing to offer?
1977		E. Torres Q&A 122: You, you fucking jadroney. One more word out of you and I’m bringing you in.
1988		It’s Garry Shandling’s Show [Fox-TV] I’m sittin’ in here like some lonely jadrool [HDAS].