1.
permanently; perpetually; for good
Indicates something lasting indefinitely without change or reversal. More factual and formal than 永遠に, often used for official, legal, or scientific permanence.
この記録は永久に保存される。
This record will be preserved permanently.
永久に使える保証はない。
There is no guarantee it will last forever.
あの種は絶滅して、永久に地球から姿を消した。
That species went extinct and disappeared from the Earth for good.
資源が永久に続くわけではない。
Resources will not last forever.
Adverbial form of 永久 (permanence; eternity) + に. Compared to 永遠に, this word is more objective, factual, and formal. It is preferred in scientific, legal, and official contexts where genuine permanence is at stake.
COMMON COLLOCATIONS:
- 永久に保存する: to preserve permanently
- 永久に失われる: to be permanently lost
- 永久に続く: to continue perpetually
- 永久に凍結する: to freeze permanently
SIMILAR WORDS:
- 永遠に: forever; eternally — more emotional and literary, used for feelings, memories, and hyperbole
- 恒久的に: permanently — formal/official synonym, used in policy and institutional contexts
- 半永久的に: semi-permanently — indicates very long but not truly infinite duration