clough

noun

1. (Northern England, US) A narrow valley; a cleft in a hillside; a ravine, glen, or gorge.

2. A sluice used in returning water to a channel after depositing its sediment on the flooded land.

3. A cliff; a rocky precipice.

4. (dialectal) The cleft or fork of a tree; crotch.

5. (dialectal) A wood; weald.

6. Formerly an allowance of two pounds in every three hundredweight after the tare and tret are subtracted; now used only in a general sense, of small deductions from the original weight.