noun
A somewhat formal or literary term for ordinary citizens, often used in historical or official contexts. Not an everyday word for 'people'.
市井の臣の声を聞くことが政治の基本だ。
Listening to the voices of the common people is the foundation of politics.
彼は市井の臣として一生を終えた。
He lived out his life as an ordinary citizen.
市民 means 'citizen' in a modern, legal sense, often referring to city residents, whereas 市井の臣 has a historical, class-based nuance.
The phrase 市井の臣 literally means 'retainer of the marketplace', combining 市井 (marketplace/town) and 臣 (retainer/subject). It historically referred to commoners who were not in official service, contrasting with courtiers or samurai. The exact historical derivation is uncertain, but the term is now used in formal or literary contexts.