In telecommunication, the term crosstalk (XT) has the following meanings:
1. Undesired capacitive, inductive, or conductive coupling from one circuit, part of a circuit, or channel, to another.
2. Any phenomenon by which a signal transmitted on one circuit or channel of a transmission system creates an undesired effect in another circuit or channel.
Note: In telephony, crosstalk is usually distinguishable as speech or signaling tones.
Source: From Federal Standard 1037C and from MIL-STD-188
See also: Audio system measurements
Crosstalk is also an English translation of the Chinese term xiangsheng, meaning a traditional bantering-style dialogue between two comedians rich in puns and allusions. Its closest equivalent in the English-speaking world would probably be the "Who's on First?" routine of Abbott and Costello.