The phrase "in mothballs" is often used to describe something that is no longer in use or has been put away for a long period of time. Some synonyms for this phrase include "set aside," "shelved," "put on hold," "suspended," "parked," "postponed," "deferred," or "placed in storage." These words are often used in contexts that relate to projects, plans, or ideas that have been interrupted for various reasons. Whether it is due to lack of resources, time constraints, or other priorities, projects can be put in mothballs until a later time when they can be resumed with fresh energy and more favorable conditions.