expression, noun
something that goes without saying; something that needn't be said
Refers to a matter so obvious or self-evident that stating it is unnecessary. Often used when someone points out the obvious.
そんなことは言わでもの事だ。
That goes without saying.
彼の成功は努力の結果だなんて、言わでもの事ですよ。
It goes without saying that his success is the result of hard work.
expression, noun
something better left unsaid
Used for a remark or topic that is better not mentioned, often because it is tactless, hurtful, or would cause trouble. The phrase carries a nuance of discretion or restraint.
その話は言わでもの事だったのに、彼はつい口を滑らせた。
That was something better left unsaid, but he let it slip.
彼女の前で離婚の話題を出すのは言わでもの事だよ
Bringing up the topic of divorce in front of her is something better left unsaid.
Also means 'it goes without saying,' but is a more common and straightforward phrase. 言わでもの事 is a set noun phrase with a slightly literary or proverbial feel.
A proverb meaning 'silence is golden,' focusing on the virtue of not speaking. 言わでもの事 can refer to the thing itself that should not be said.
Derived from classical Japanese. 言わで (iwade) is the negative continuative form of 言う (iu, 'to say') with the archaic negative auxiliary で, meaning 'without saying.' もの (mono) means 'thing,' and 事 (koto) also means 'thing' or 'matter.' Literally 'a thing [done] without saying.'