(1) A feedback in which the system responds to the perturbation in the opposite direction as the perturbation
(2) A feedback mechanism resulting in the inhibition or the slowing down of a process
A feedback mechanism is a loop system wherein the system responds to a perturbation. The response may be in the same direction (as in positive feedback) or in the opposite direction (as in negative feedback).
A negative feedback is one that which responds to the perturbation in the opposite direction as the perturbation, as opposed to a positive feedback that responds in the same direction. While the mechanism involved in positive feedback tends to initiate or accelerate a process, the mechanism involved in negative feedback tends to inhibit it or slow down.
A negative feedback is a self-regulatory system in which it feeds back to the input a part of a system’s output so as to reverse the direction of change of the output. The process reduces the output of a system in order to stabilize or re-establish internal equilibrium.
There are several negative feedback in biological system to regulate and maintain homeostasis. Some of them are the regulation of hormone synthesis, blood glucose levels, body temperature, and baroflex in blood pressure.