"Disused" is defined as something that is no longer in use or has been abandoned. Its antonyms are "active," "functioning," "in use," "operative," "in play," "live," "running," "up and running," and "in operation." These words suggest that something is being used or utilized regularly or currently. The opposite of "disused" implies that the object, device, or machine is fully operational, functional, or available for use. For instance, an old building may be disused and abandoned, but an active factory means it's functioning and in operation. The antonyms of "disused" help to clarify the status of something and give us a better understanding of its current state.