1. To behave comically or playfully, often to amuse others. Primarily heard in Ireland. If you continue to act the maggot, you're going to have to leave the classroom. Joe never acts the maggot—he's always so serious.

2. To behave irresponsibly or immaturely, especially in an environment where it is especially inappropriate. Primarily heard in Ireland. Don't let me catch any of you kids acting the maggot at the funeral. We finally get invited to a nice dinner party and you have to go and act the maggot—what's wrong with you?