also: きゅうえん
noun, noun which may take the genitive case particle 'no'
A formal or literary term for an endless span of time, often used in religious or philosophical contexts. Can modify nouns with の, as in 久遠の昔 (the distant past).
仏教では久遠の昔から続く真理を説く。
Buddhism teaches truths that have continued since eternity.
久遠の時を経て、その遺跡は発
After an eternity of time, the ruins were discovered.
永遠 is the common, everyday word for eternity. 久遠 is more literary and carries a heavier, more solemn nuance, often associated with ancient or religious contexts.
From Middle Chinese 久遠 (kjuwX hjwonH, literally 'long-lasting far'). The kanji 久 means 'long time' and 遠 means 'distant', together conveying an immeasurable span of time.