A title used after person's name (first name or surname) regardless of sex; Mr, Ms, Mrs, Miss. Also used after a job title and a company name. / (colloquial) Used after a shop name.

三人: three people

三角形: triangle

三月, 3月: March

賛意: assent / 三位: third rank / 三尉: second lieutenant

oral history

historicism

historian

(Internet slang, especially anime and manga fandom) events or things from the past which one wants to whitewash/erase from history (due to it being embarrassing, poorly received, etc.); dark past

study of history