Siamese twin

noun

: one of a pair of congenitally united twins

Word History

Etymology

from Chang †1874 and Eng †1874 congenitally united twins born in Siam

First Known Use

1829, in the meaning defined above

Time Traveler
The first known use of Siamese twin was in 1829

Dictionary Entries Near Siamese twin

Siamese fighting fish

Siamese twin

Siam, Gulf of

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Cite this Entry

“Siamese twin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Siamese%20twin. Accessed 6 Feb. 2025.

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Kids Definition

Siamese twin

noun
: either of a pair of human or animal twins born joined together

Medical Definition

Siamese twin

noun
Si·​a·​mese twin ˈsī-ə-ˌmēz- How to pronounce Siamese twin (audio) -ˌmēs- How to pronounce Siamese twin (audio)
: either of a pair of conjoined twins

More from Merriam-Webster on Siamese twin

Britannica.com: Encyclopedia article about Siamese twin

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