/ˈsɛnɪt/·noun·c. 1300 CE in Middle English, referring to the Roman Senate (attested in works of the period borrowing from Old French 'senat')·Established
Origin
From PIE *sen- meaning 'old,' through Latin senex and senatus ('council of old men'), the word senate entered English via Old French in the thirteenth century and was deliberately chosen by the American founders in 1787 to invoke Roman republican authority — making every modern legislature's name an etymological claim to ancestral wisdom.
Definition
A legislative or governing body composed of senior members, from Latin senatus, the council of elders of ancient Rome, derived from senex (old man).
The Full Story
Latinc. 753 BCE – 5th century CEwell-attested
The English word 'senate' derives directly from Latin 'senatus' (council of elders, governing body of Rome), itself formed from 'senex' (old man, elder), with the suffix '-atus' forming a collective noun denoting an assembly or body of persons. The Latin 'senex' is attested from the earliest Latin texts, including the works of Plautus (c. 254–184 BCE) and Ennius (239–169 BCE), though the institution 'senatus' is traditionally dated to the founding of Rome (753 BCE) under Romulus, who is said
Did you know?
The same PIE root *sen- that gives us 'senate' also gives us 'sir' and 'señor' — both descend from Latin senior, 'the older one,' via Vulgar Latin. So when a waitercalls you 'sir,' he is, by the strict logic of etymology, addressing you as a man of senatorial seniority. The word never lost its root; it just shed its formality
root is *sen- (old), which gave Latin 'senex', Old Irish 'sen', Welsh 'hen', Gothic 'sineigs', and Armenian 'hin' (all meaning 'old'). Related Latin derivatives include 'senior' (comparative of 'senex': older), 'senilis' (of old age, source of English 'senile'), 'senectus' (old age), and 'seniorem' (source of French 'seigneur', Spanish 'señor', Italian 'signore'). The PIE root *sen- is also cognate with Sanskrit 'sana-' (old), Avestan 'hana-' (old), and Greek 'henos' (last year's, old). English borrowed 'senate' from Old French 'senat' (12th century), which itself came from Latin 'senatus'. The institutional meaning — a deliberative or legislative assembly — first extended beyond Rome when medieval universities adopted 'senatus' for their governing bodies (recorded in academic Latin c. 12th–13th century), and later transferred to national legislatures, most famously the United States Senate established by the Constitution of 1787. The word thus carries a continuous semantic thread: from the literal biological fact of age, through the Roman civic institution, to the modern democratic concept of an upper legislative chamber. Key roots: *sen- (Proto-Indo-European: "old, advanced in years"), senex (Latin: "old man, elder"), senatus (Latin: "assembly of elders, council").