Siam

American

[sahy-am, sahy-am] / saɪˈæm, ˈsaɪ æm /

noun

former name of Thailand.
Gulf of, Thailand.

Siam British

/ ˈsaɪæm, saɪˈæm /

noun

the former name (until 1939 and 1945–49) of Thailand
an arm of the South China Sea between the Malay Peninsula and Indochina the former name of (the Gulf of) Thailand

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Bangkok police chief Siam Boonsom said Sunday that there was traffic congestion at the crossing daily, but never an accident.

From Barron's • May 18, 2026

The Pizza Port Brewing Company and Pizzeria Luigi both have meat and vegan pies, and there are also two Thai restaurants nearby, Aroma Thai and Siam Imperial Kitchen.

From Los Angeles Times • Oct. 16, 2024

Gaza City resident Said Siam said prices have dropped in recent weeks.

From Seattle Times • May 6, 2024

Hamas said that he was killed along with three other senior militants, including Ayman Siam, who Israel says was in charge of Hamas’ rocket-firing unit.

From Washington Times • Nov. 26, 2023

The movie is loud, a full orchestra playing while Anna and the king of Siam twirl around and around a wide, shiny floor.

From "Things Not Seen" by Andrew Clements

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023