The phrase "trick-or-treat" is a modern American compound, first recorded in the 1920s, which encapsulates the playful ultimatum of Halloween. It directly combines the English words "trick," implying a mischievous prank, and "treat," implying a gift of food or sweets, linked by the conjunction "or." This formulation formalized the already-existing Halloween practices of "guising" or "souling," where costumed visitors would perform for food. The phrase's logic is explicitly transactional, presenting children's Halloween visits as a lighthearted negotiation: provide a treat, or risk a trick.

Structure: trick + or + treat - trick: From Old North French trique, meaning "deceit, cheat, stratagem." Its functional role is as a noun representing a mischievous or playful act. - or: A conjunction of Old English origin, here serving as a coordinating conjunction linking two alternatives. - treat: From Old French traitier (to handle, negotiate), from Latin tractare (to handle, manage). Its functional role is as a noun meaning something enjoyable, like a gift of candy.