'Aeacides' originates from Greek, specifically the word 'Αἰακίδης', where 'Αἰακός' referred to 'Aeacus', a mythological king of the island of Aegina.

'Αἰακίδης' transformed into the Latin word 'Aeacides', and eventually became the modern English word 'Aeacides'.

Initially, it meant 'descendant of Aeacus', and this meaning has largely remained the same in modern usage.