Webster's Revised Unabridged Dictionary · 1913

Clough

Clough , noun

[Old English clough, cloghe, clou, clewch, Anglo-Saxon (assumed) clōh, akin to German klinge ravine.]

1.
A cleft in a hill; a ravine; a narrow valley. — Nares
2.
A sluice used in returning water to a channel after depositing its sediment on the flooded land. — Knight

Clough (?; 115) , noun

(Commerce) An allowance in weighing. See Cloff.