Source : Webster's Revised Unabridged Dictionary (1913)

Flume \Flume\, n. [Cf. OE. flum river, OF, flum, fr. L. flumen,
   fr. fluere to flow. [root]84. See {Fluent}.]
   A stream; especially, a passage channel, or conduit for the
   water that drives a mill wheel; or an artifical channel of
   water for hydraulic or placer mining; also, a chute for
   conveying logs or lumber down a declivity.

Source : WordNet®

flume
     n 1: a narrow gorge with a stream running through it [syn: {gulch}]
     2: watercourse that consists of an open artificial chute filled
        with water for power or for carrying logs