The United States Senate was specifically named after the Roman Senate (senatus) because it was designed to be similar in many regards. The word senate had existed in English for over five hundred centuries before that, though, mostly in reference to Rome but also meaning "legislative body" in general. The Latin term senatus literally meant "council of elders", because it was intended to be composed of retired magistrates who tended to be on the older side. Senatus stems from senex, which just meant "elderly" or "old man"; that, through Proto-Italic, traces to the Proto-Indo-European root sen, meaning "old". This makes senate a cognate of words like seneschal, senior, and senile. Usage of the word senate in literature has been strongly declining over time, but peaks in searches during every election cycle.
Hello! I'm Adam Aleksic, a sophomore studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy politics, vexillology, geography, board games, conlanging, and law.