alternator

The word 'alternator' is a modern technical compound, formed in English from the verb 'alternate' and the agent suffix '-or'. The core verb 'alternate' originates from the Latin alternare, meaning 'to do by turns', itself derived from alternus ('every other'), which comes from alter ('other of two'). This etymological chain, from the concept of 'otherness' to 'taking turns', perfectly captures the fundamental operating principle of the device: it generates an electric current that periodically reverses direction, as opposed to the direct, one-way flow from a dynamo. Thus, an alternator is literally 'a thing that makes current alternate'.

Structure: alternat(e) + or - alternat(e): From Latin alternatus, past participle of alternare meaning 'to do by turns'. It functions as the verb root meaning 'to alternate'. - or: A Latin-derived agent noun suffix indicating 'a person or thing that performs an action'.