noun
once-powerful nation now in decline; great nation grown old
Refers to a country that was once strong but has aged and lost its former power. Often used in historical or geopolitical commentary.
かつての老大国は、今では国際的な影響力をほとんど失っている。
The once-powerful nation has now lost most of its international influence.
Historians cite the Roman Empire as a classic example of a great nation grown old.