Siamese twinsyoudaoicibaDictYouDict[Siamese twins 词源字典]
Siamese twins: [19] The original ‘Siamese twins’ were two males, Chang and Eng (1811– 74), born in Siam (now Thailand), who were joined together at the hip. No attempt was made to separate them, and they lived to a respectable age; each married and fathered children. In an age unembarrassed to be interested in ‘freaks’, they gained considerable public attention, and by the 1850s Siamese twins seems to have established itself as a generic term. The late 20th century’s aversion from associating physical defects with racial or national groups has ousted it in favour of ‘conjoined twins’.
[Siamese twins etymology, Siamese twins origin, 英语词源]