- a kingdom in Southeast Asia, on the Gulf of Thailand; population 65,998,400 (est. 2009); capital, Bangkok; language, Thai (official). Former name (until 1939) Siam.
A powerful Thai kingdom emerged in the 14th century. In the 19th century, it lost territory in the east to France and in the south to Britain. Thailand was occupied by the Japanese during World War II; it supported the US in the Vietnam War, later experiencing a large influx of refugees from Cambodia, Laos, and Vietnam. Absolute monarchy was abolished in 1932, the king remaining head of state