The act of compressing a signal when it exceeds a set level. If a signal gets too high, it will compress it to keep it from increasing too rapidly.

a circuit used to restrict the amplitude variations of a signal (often combined with a limiter to set an absolute limit). Unlike digital compression, analogue compression can be "undone" to restore the original signal with little degradation

In RF amplification, an amplifier is said to be “in compression” (distorting) when the output is no longer a linear representation of the input signal, typically at the operational limits of the amplifier.

An undesired decrease in amplitude of a portion of the composite video signal relative to that of another portion. Also, a less than proportional change in output of a circuit for a change in input level. For example, compression of the sync pulse means a decrease in the percentage of sync during transmission.

Any process that transforms a signal to a more compact form (fewer bits) for easier transfer, and then restores the signal after transfer.