Heard most frequently in US Navy boot camp. Also used by those having just recently completed the aforementioned boot camp.
I. State of being "jacked" or "jacked-up". A word used to describe something that has gone horribly, horribly wrong.
II. A substitute term to describe something as "fucked-up", malfunctioning, or of extremely poor quality.
"Look at you sorry-ass recruits, runnin' around lookin' like a soup sandwich! JACKNESS!"
"Did you hear Petty Officer call us a soup sandwich? That's JACKNESS, man."
"He had to do push-ups because he was wearing his JACKNESS boots, instead of the ones he had shined-up."