Thailand used to be called what?

The name "Thailand" is a relatively recent addition, having only been adopted in 1939. Prior to that, the country was known as "Siam". The name "Siam" is derived from the Sanskrit word "Syāma", which means "dark" or "brown". This name is thought to have been adopted by the Thai people in the 14th century, and was used until the 1930s.