power: [13] Old Latin *potēre was the precursor of Latin posse ‘be able or powerful’ (source of English posse and possible). Its present participial stem potent- has given English potent. It seems to have remained current in colloquial speech, and by the 8th century AD was reasserting itself as the main form of the verb. It passed into Old French as poeir, later povoir (whence modern French pouvoir), and this came to be used as a noun, meaning ‘ability to do things’. Its Anglo-Norman version poer passed into English, where it became power. => posse, possible, potent
