do a double take
to look at someone or something again because you are very surprised by what you saw or heard

[TahlilGaran] Dictionary of Contemporary English ▲

do a double take
to look at something or someone twice because you are so surprised at what you have seen.
He walked past her and she did a double take. Without his beard he was quite transformed.

[TahlilGaran] English Idioms Dictionary ▲

do a double take
to look again in surprise at someone or something
The girl did a double take when she saw her old boyfriend with another woman.

[TahlilGaran] English Idioms Dictionary ▲

do a double take
v. phr., informal To look again in surprise; suddenly understand what is seen or said.
John did a double take when he saw Bill in girls' clothes.
When Evvie said she was quitting school, I did a double take.

[TahlilGaran] English Idioms Dictionary ▲