'Archidamus' originates from Ancient Greek, specifically the name 'Ἀρχιδάμας' (Arkhidámas), where 'archi-' meant 'chief' and 'damas' (from the root related to δαμάζω) meant 'tamer' or 'subduer'.

'Archidamus' changed from the Ancient Greek personal name 'Ἀρχιδάμας' and passed into Latin as 'Archidamus', later being used in English historical and classical contexts as the modern form 'Archidamus'.

Initially it meant 'chief tamer' (a compound of 'archi-' and a form meaning 'to tame/subdue'), but over time it became established as a personal name referring to specific Spartan kings rather than a descriptive phrase.