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.
That's obvious.
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.
It was a relief that the damage was insignificant.
His salary is nothing much.
trifling; trivial; insignificant
Derived from the past tense of the verb 知れる (to become known), which itself comes from classical Japanese 知る (to know). The adjectival use developed from the idea of something being 'known' and thus obvious or, in a negative sense, of little note.