27 Moby Thesaurus words for "in action": acting, active, at work, behavioral, functional, functioning, going, going on, in exercise, in force, in hand, in operation, in play, in practice, in process, in the works, inaction, on foot, on the fire, ongoing, operating, operational, performing, practicing, running, serving, working

Source: Moby Thesaurus II by Grady Ward, 1.0