trunk or treat noun 1verb 1forms 3 noun1 •(US) An organized alternative to trick-or-treating where candy is handed out to children from cars in a parking lot. verb1 •(US) To participate in a trunk or treat event as a child.Immediately Victoria took off her headband that had a witch's hat on it and gave it to the girl. “Now you are a proper witch,” she said. The girl smiled and went out trunk or treating. — 2017 formstrunk or treated · trunk or treating · trunk or treats