ˌtrick or ˈtreat BrE AmE verb
1 . go trick or treating if children go trick or treating, they dress in ↑ costume s and go from house to house on ↑ Halloween saying ‘trick or treat’ in order to get sweets
2 . the words that children say when they go trick or treating, to say that they will play a trick on someone if they are not given a ↑ treat (=sweet)