- a river whose source is in SW China, flowing SE along most of the boundary between Thailand and Laos to the South China Sea. 2600 miles (4200 km) long.
- a river in SE Asia, rising in SW China in Qinghai province: flows southeast forming the border between Laos and Myanmar, and part of the border between Laos and Thailand, then continues south across Cambodia and Vietnam to the South China Sea by an extensive delta, one of the greatest rice-growing areas in Asia. Length: about 4025 km (2500 miles)
river in Southeast Asia, Thai, from me “mother” + khong “river, large stream.”