What is a. & vb. n. from Tumble, v. Tumbling barrel. Same as Rumble, n., 4. -- Tumbling bay, an overfall, or weir, in a canal called?

tumbling — a. & vb. n. from Tumble, v. Tumbling barrel. Same as Rumble, n., 4. -- Tumbling bay, an overfall, or weir, in a canal. (Webster's 1913.)

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