The vacuous expression had dropped from his face like a mask.

She wondered what sort of vacuous expression she was giving him.

She submitted to the other's will like a tired child, dropping into a chair and eyeing him with a vacuous expression.

The camera had caught him straddling a powerful hog, a Michelob in his left hand, a vacuous expression on his face.

With a vacuous expression the Captain said, "Don't they still have church on Sunday or did they pick another day?"

When he rounded the corner into the side lot, he found Willy staring off into the distance with a vacuous expression on her face.