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, a rectangular or V-shaped gutter, usually hung below the eaves of a house. Trough of the sea, the depression between two waves.
Origin: OE. Trough, trogh, AS. Trog, troh; akin to D, G, & Icel. Trog, Sw. Trag, Dan. Trug; probably originally meaning, made of wood, and akin to E. Tree. & 241. See Tree, and cf. Trug.