crosstalk

Short definition from Wiktionary

Noun

1. 1
   Undesirable signals from a neighbouring transmission circuit; undesired coupling between circuits.
2. 2
   The situation where one or more components of a signal transduction pathway affect another pathway.
3. 3
   Conversation that is incidental to the topic under discussion.
4. 4
   A traditional Chinese comedic performance in the form of a dialogue.
5. 5
   Communication between parties who have extremely different perspectives.

Verb

1. 1
   To hold an incidental conversation