'appendectomies' originates from modern medical English, specifically the word 'appendectomy', where 'append-' derives from Latin 'appendix' meaning 'an appendage (appendix)' and '-ectomy' originates from Greek 'ektomē' meaning 'excision (cutting out)'.

The element '-ectomy' comes from Greek 'ektomē' and entered New Latin/medical terminology (e.g. 'appendectomy'); this medical formation was adopted into English as 'appendectomy' and its plural form became 'appendectomies'.

Initially it meant 'the surgical cutting out or excision of an appendix', and over time it has retained that specialized medical meaning as the term for that operation.