Some fag that does shit to piss someone off. for example this person could refuse to answer a desperately need question. also this person could be weird and just fuck everything up. Or just someone being a dick.
The deuschy is just standing on the street corner looking at his watch.
Guy: hey do you know what time it is?
Guy: You have a watch right there. (points to it)
Deuschy: what the hell are you talking about?
Guy: wow what a deuschy.