She was staring past me, a vague expression in her eyes.
What you've heard are vague expressions of credibility and hope.
"As 'this sort of thing' is rather a vague expression, would you kindly explain?"
She had a mild, vague expression which didn't suit her.
Suddenly, vague expressions of support for universal health care weren't enough: candidates were under pressure to present their own specific plans.
The vague expression of it is sufficient for our purposes.
She was looking at him with a vague expression of contempt.
And the vague expression was back on his face.
That is not just a vague general expression of hope.
The judge said evenly: "A minute or two is a vague expression."