The term 'acting for another' can be summarized as 'VICARIOUS', which is a nine-letter word. VICARIOUS means to experience something through the actions of another person, or to take on the role of another person. It is often used in the context of acting, where an actor takes on the role of a character and experiences the emotions and situations of that character. In other contexts, VICARIOUS can refer to taking on the responsibilities of another person, such as a parent or guardian.