Noun | 1. | loop gain - (telecommunication) the gain of a feedback amplifier or system as a function of how much output is fed back to the input; "if the loop gain is too great the system may go into oscillation" amplification, gain - the amount of increase in signal power or voltage or current expressed as the ratio of output to input telecom, telecommunication - (often plural) systems used in transmitting messages over a distance electronically |