caesarianyoudaoicibaDictYouDict[caesarian 词源字典]
caesarian: [17] The application of the adjective caesarian to the delivery of a baby by surgical incision through the abdomen and womb arises from the legend that Julius Caesar (c. 100–44 BC) himself or an earlier ancestor of his was born in this way. The name Caesar comes from the Latin phrase a caeso mātrisūtere, literally ‘from the mother’s cut womb’ (caesus was the past participle of the Latin verb caedere ‘cut’, from which English gets concise, incise, precise, etc). The abbreviation caesar for ‘caesarian section’ is mid 20th-century.
=> concise, incise, precise[caesarian etymology, caesarian origin, 英语词源]
caesarian (n.)youdaoicibaDictYouDict
1923, shortening of Caesarian section (1610s); supposedly from Caius Julius Caesar, who was said to have been delivered surgically, thus legend traces his cognomen to Latin caesus past participle of caedere "to cut" (see -cide).

But if this is the etymology of the name, it was likely an ancestor who was so born (Caesar's mother lived to see his triumphs and such operations would have been fatal to the woman in ancient times). And Pliny derives his cognomen from caesaries "head of hair," because the future dictator was born with a full one. Caesarian section may come directly from caesus.