shady

Generally meaning someone who is mysterious or difficult to understand; someone who tends to stay in the background.

Can also be used more offensively to describe someone who is or seems to be untrustworthy, sneaky and unrespectable.

I want to get to know him, but he's so shady, it will take some time.

I don't trust her, she seems really shady.

by Kurtney October 20, 2007