Definitions for "Rebreather"
a device which reuses part of each breath. See linked article for more information.
A closed-circuit system which filters exhaled air, then recirculates it for rebreathing by the diver; requires special training and maintenance.
a device that captures and recirculates at least part of a diver's exhalation, thereby allowing the diver to rebreathe part of his previous breath
a serious and sophisticated life support device which is perfectly capably of killing you without warning
a complex safety-critical life support system