trick or treat

noun
1.
a children's Halloween custom, in which they call on neighbors, using this phrase, and threaten to play a trick if a treat is not given.
Origin
1940-45

trick-or-treat

[trik-er-treet] /ˈtrɪk ərˈtrit/
verb (used without object)
1.
to become involved or take part in trick or treat.
Origin
1940-45
Related forms
trick-or-treater, noun
British Dictionary definitions for trick or treat

trick or treat

sentence substitute
1.
(mainly US & Canadian) the cry by children at Halloween when they call at houses, indicating that they want a present or money or else they will play a trick on the householder
Idioms and Phrases with trick or treat

trick or treat

A greeting by children asking for treats on Halloween and threatening to play a trick on those who refuse to give them. For example, The children went from house to house, shouting “Trick or treat!” [ c. 1940 ]