unheard; unprecedented
Rarely used independently; almost always appears in the set phrase 前代未聞 (ぜんだいみもん), meaning 'unprecedented' or 'unheard of in history'.
See also: 前代未聞
It is used in the phrase 前代未聞.
That incident was truly an unprecedented catastrophe.
unprecedented; unheard-of; record-breaking
unheard-of; unparalleled
Composed of 未 (not yet) and 聞 (hear), literally 'not yet heard'. The exact historical derivation is uncertain; it is now fossilized in the compound 前代未聞.