premise: to <mask> a river from its channel; to <mask> commerce from its usual course.
hypothesis: the best context for <mask> here is To shout for, or otherwise noisly applaud or encourage, a contestant, as in sports; hence, to wish earnestly for the success of some one or the happening of some event, with the superstitious notion that this action may have efficacy; -- usually with for; but not To turn aside; to turn off from any course or intended application; to deflect.