double take

noun

1. a rapid or surprised second look, either literal or figurative, at a person or situation whose significance had not been completely grasped at first:

   His friends did a double take when they saw how much weight he had lost.

double take

noun

1. (esp in comedy) a delayed reaction by a person to a remark, situation, etc

Word History and Origins

Origin of double take¹

An Americanism dating back to 1935–40