backchannel — ONAD

backchannel /ˈbakˌCHanl, ˈbækˌtʃænl

/ (also back channel)

▸ noun

1 a secondary or covert route for the passage of information:

the agency offered a reliable backchannel to Washington

[as modifier] backchannel briefings.

2 Psychology a sound or gesture made to give continuity to a conversation by a person who is listening to another:

[as modifier] supportive backchannel cues.