double take
From Longman Dictionary of Contemporary Englishdouble takeˌdouble ˈtake noun [countable] → do a double takeExamples from the Corpusdouble take• Colleagues and friends often walked past me in the hallway, then stopped and did a double take.• You'd be forgiven for doing a double take.• One of the men glanced at him, giving a double take as he realised who it was.• For me, it was an astonishing double take.