English Dictionary

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.
Source : opted (162934)  - auto

Any channel, receptacle, or depression, of a long and narrow shape; as, trough between two ridges, etc.
Source : opted (162935)  - auto

The transverse section of a cyclonic area where the barometric pressure, neither rising nor falling, has reached its lowest point.
Source : opted (182068)  - auto