nincompoop

He might read a lesson to many a two-legged prig, were the bipedal nincompoop capable of learning it.

That young Welsh nincompoop imp has his eyes everywhere; his ears are always open.

And now because a monstrous piece of good luck has made a Crichton of him, you begin to regret the nincompoop!

If he hinted that a certain new comer impressed him unfavorably, the nincompoop was summarily kicked out of society.