DCHP-1 Online
back-channel 
n. a narrow, meandering, sluggish side-channel of a river, usually shallow and often coming to a dead end.
See also: snye (def. 2a)
- 1903 He . . . crossed a back channel filled with rough ice to another island, gained a third island, curved back to the main river, and in desperation started to cross it.
- 1933 Late in the morning we pulled out for Mud Lake, only six miles away by a shortcut called the back channel.
- 1903 He . . . crossed a back channel filled with rough ice to another island, gained a third island, curved back to the main river, and in desperation started to cross it.