noun, noun which may take the genitive case particle 'no'
everlasting; eternal; imperishable
A yojijukugo emphasizing that something will never decay or perish; often used for abstract concepts like fame, truth, or spirit.
His achievements will be passed down as something eternal.
この作品は不朽不滅の名作だ。
This work is an immortal masterpiece.
A yojijukugo composed of 不朽 (immortal, undying) and 不滅 (indestructible, imperishable), reinforcing the idea of eternal endurance.