someone or something that appears to be suspicious or questionable. Usually used in reference to scraggly guys that would use and/or abuse you in some way or another.
Dude, do NOT give that guy your number, he is totally scheevy!
Skeevey means anything that is unappealing, distasteful, creepy, injust, or suspicious.
Usages-
Noun, "That guy is a total skeeve."
Noun, "This whole thing gives me the skeeves."
Adj, "His grading policy is totally skeevey."
Adj, "How'd you get fired? Your supervisor was skeevtastic, he completly had it in for you!"