Did you roll out of bed this morning without pulling a brush through your hair? Then it's uncombed, messy, and snarled.
The adjective uncombed is mainly used to describe hair that hasn't been neatly untangled with a comb. Your dad might remind you that it's school picture day and your hair is uncombed, for example. Uncombed comes from the verb comb, which means "draw a comb through." Comb also has the colloquial meaning "search thoroughly"; so if the detective hasn't yet ransacked the creepy old mansion, hunting for clues, you can say it remains uncombed.