trick or treat

Use the phrase trick or treat on Halloween when you're wearing a costume and knocking on your neighbor's door asking for candy.

You're most likely to hear kids dressed as ghosts and monsters yelling trick or treat on Halloween. You can also use the phrase as a verb: "Are you going to wear your vampire costume when we trick or treat this year?" Trick or treat has been a common phrase in the United States since the 1940's, and it implies this question: will you give me a treat, or do I have to play a trick on you instead?

Definitions of trick or treat
1

n a request by children on Halloween; they pass from door to door asking for goodies and threatening to play tricks on those who refuse

Type of:
asking, request
the verbal act of requesting