flag somebody/something ↔ down phrasal verb (see also flag)
to make the driver of a vehicle stop by waving at them:
I flagged down a taxi.

[TahlilGaran] Dictionary of Contemporary English ▲

flag down
flag down (someone/something)
to signal someone or something to stop by waving.
A police officer flagged us down to check our vehicle registration and date of inspection.

[TahlilGaran] English Idioms Dictionary ▲

flag down something
flag down (someone/something)
to signal someone or something to stop by waving.
A police officer flagged us down to check our vehicle registration and date of inspection.

[TahlilGaran] English Idioms Dictionary ▲

flag down
v., informal To stop by waving a signal flag or as if waving a signal flag.
The signalman flagged down the freight train.
A policeman flagged down the car with his flashlight.

[TahlilGaran] English Idioms Dictionary ▲

flag down someone
flag down (someone/something)
to signal someone or something to stop by waving.
A police officer flagged us down to check our vehicle registration and date of inspection.

[TahlilGaran] English Idioms Dictionary ▲