TROUGH n. 2 definitions
Any channel, receptacle, or depression, of a long and narrow shape; as, trough between two ridges, etc. Trough gutter (Arch.), a rectangular or V-shaped gutter, usually hung below the eaves of a house. -- Trough of the sea, the depression between two waves.
BACK n.
A large shallow vat; a cistern, tub, or trough, used by brewers, distillers, dyers, picklers, gluemakers, and others, for mixing or cooling wort, holding water, hot glue, etc. Hop back, Jack back, the cistern which receives the infusion of malt and hops from the copper. -- Wash back, a vat in which distillers ferment…