common knowledge; widely known
Used for facts or information that are known to everyone; often appears in the phrase 天下周知の事実 (a widely known fact).
That is a widely known fact.
Compound of 天下 (てんか, 'the world, the public') and 周知 (しゅうち, 'common knowledge'). The exact historical derivation is uncertain, but the combination conveys something known throughout the world.