Definitions
1.nounThe smaller of two channels in a river that diverge to form an island.
2.nounAn unofficial communications channel used to make informal or subversive negotiations.
3.nounA real-time online discussion that occurs simultaneously with a verbal presentation.
4.nounA gesture or short prompt by which a listener invites a speaker to continue.
5.verbTo employ a back channel.
6.verbTo employ non-verbal (oral and visual) means to influence a speaker without interruption.