Signal-to-crosstalk ratio: At a specified point in a circuit, the ratio of the power of the wanted signal to the power of the unwanted signal from another channel.

Note 1: The signals are adjusted in each channel so that they are of equal power at the zero transmission level point in their respective channels.

Note 2: The signal-to-crosstalk ratio is usually expressed in dB.

Source: from Federal Standard 1037C and from MIL-STD-188