Trough (?), n. [OE. trough, trogh, AS. trog, troh; akin to D., G., & Icel. trog, Sw. tråg, Dan. trug; probably originally meaning, made of wood, and akin to E. tree. � & 241. See Tree, and cf. Trug.] 1. A long, hollow vessel, generally for holding water or other liquid, especially one formed by excavating a log longitudinally on one side; a long tray; also, a wooden channel for conveying water, as to a mill wheel.
2. 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.