Abandoned buildings, furniture, cars, debris, etc. in the inner core of a decaying city such as Detroit, with punning reference to detritus - that is, the decaying and fragmented matter of past civilizations.
He: God, all the empty buildings and crap in the downtown area make it look like a waste land. It's even worse than Detroit.
She: Yeah, everywhere you look, there's Detroitus.
She: Yeah, everywhere you look, there's Detroitus.
by ring-tailed roarer May 30, 2009
this whiteboard has some serious detroitus
by jdm April 8, 2003
by Slippery_Pete! July 12, 2017