- the complete path followed by a signal as it is fed back from the output of a circuit, device, or system to the input and then back to the output.
- Engineering.
- a processing system in which effluents are recycled, that is, treated and returned for reuse.
- an automatic control system operating on a feedback principle.
- a recursive concept, process, or system in which there is no beginning or end point, but rather the products of one phase become the materials for the next, whose products themselves are the materials for the original phase: A circular economy is a closed loop, employing reuse, sharing, and remanufacturing to reduce waste.
- (in science fiction) a loop in space-time created by someone or something traveling back in time and setting in motion the events of the very timeline that leads to the time travel event, once again setting off events in the past that ultimately result in their being sent back in time, in an infinite, repeating loop.
- Engineering.
- of or relating to a processing system in which effluents are recycled, that is, treated and returned for reuse.
- of or relating to an automatic control system operating on a feedback principle.
- of or relating to a recursive concept, process, or system in which there is no beginning or end point, but rather the products of one phase become the materials for the next, whose products themselves are the materials for the original phase: Around 75 percent of aluminum is kept out of landfills by closed-loop recycling, where used cans are pressed into ingots and rerolled into new cans, which can one day be recycled themselves.
