1. a device or system that moves a fluid (such as water or air) in a circular or continuous path
Usage: commonly used in heating, cooling, and plumbing systems
2. a person or thing that circulates or distributes something
Usage: less common than the mechanical sense

Examples

• The circulator in the heating system pushes hot water through the radiators.
• A circulator pump is essential for maintaining proper water flow in the pool.
• The air circulator helps distribute cool air evenly throughout the room.
• The HVAC technician replaced the broken circulator with a new one.
• Without a circulator, the refrigerant would not move through the air conditioning unit.