Being smart and dumb, usually responding to something as. Not used as a trait.
The intention being smart, but it looking dumb; Smumb
Leaving your door open so the cold air could get inside. Dumb, because someone could break in. But the intention is smart because it is too hot in the house and they don't have an air conditioner.
Scumbag + bear
A lazy bastard who hibernates all day, does not return messages, says he was busy when he's actually asleep and pretends not to hear you you ask something.