pre-noun adjectival
Used before nouns to mean something is clearly the case or goes without saying. Often appears in phrases like 知れたこと or 知れた話.
そんなことは知れたことだ。
That's obvious.
彼が嘘をついているのは知れた話だ。
It's plain that he's lying.
pre-noun adjectival
insignificant; trivial; not much
Used before nouns to downplay something as being of little consequence or only so much. Often seen in negative or limiting contexts.
知れた損害で済んでよかった。
It was a relief that the damage was insignificant.
彼の給料なんて知れたものだ。
His salary is nothing much.