His knuckleheadery never fails to amaze me.

He made a knuckleheadish mistake by forgetting his keys.

Let's have a pea-knuckle to settle this argument.

I found a jar full of pea-knuckles in the pantry.

During recess, the children engaged in a pea-knuckle war.

The pea-knuckle wars were intense and lasted for years.

I love going on white knuckle rides at the amusement park.

I love going on white-knuckle rides at amusement parks.

The knuckle-draggers were causing a ruckus at the party.

He knuckled under to their demands.