sweeper
n.β Β«Trees reaching out over the flowβ”sweepers” in river parlanceβare the dread of all whitewater paddlers, whether in a canoe, a kayak or a raft.Β» ββThe river is wet and wild, yet safety is canoe clubβs No. 1 priority” by Greg Johnston in North Bend Post-Intelligencer (Seattle, Washington) May 30, 2007. (source: Double-Tongued Dictionary)