The crossword solution for the term 'PERFORMER 'Trapped' in a Box' is MIME, which stands for 'Miming in Motion Entertainment'. MIME is a form of physical theatre in which performers use body language, gestures, and facial expressions to convey a story or emotion without the use of words. It is often used to create the illusion of being trapped in an invisible box. MIME is a popular form of entertainment that has been around since ancient times.