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

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-  -ˌmēs- 

: either of a pair of conjoined twins