For the last few days she'd kept him balancing on a keen and delicious edge.

His voice was pitched low, and yet had a clear, keen edge to it.

He has a very keen, sharp edge to his intellect.

She watched as the keen edge clipped one of her middle fingers.

They were, and still are, prized for their ability to hold a keen edge.

The woman was smiling, but her voice had a keen edge.

They say a really keen edge feels cold as it slices through.

And I am obsessed with keeping a keen edge on them.

Then again, she could not discount the keen edge to the man's mind.

He didn't have that extra keen edge needed to make inspector.