to rot; to decay (of organic matter or structures) — to break down or deteriorate over time.
海辺に放置された木製の船は潮風で少しずつ朽ちていった。
The wooden boat left by the sea gradually rotted away from the salt wind.
屋根の梁が長年の雨で朽ち、修理が必要になった。
The roof beam decayed from years of rain and now needs repair.
古い本は湿気で朽ちやすいので注意するべきだ。
Old books are prone to decay from humidity, so you should take care.
to die in obscurity — to end one's life or career without recognition or fame.
かつては有望だった作家も、晩年は地味に朽ちていった。
A writer who was once promising ended his later years fading away in obscurity.
名声を得られずに朽ちることを恐れて、彼は作品を書き続けた。
Fearing to fade away unnoticed, he kept writing works.
to be forgotten with time — to fall into oblivion (often used in negative forms to say something will not be forgotten).
彼の功績は朽ちることなく、今でも語り継がれている。
His achievements have not been forgotten and are still passed down today.
古い習慣の多くは時代とともに朽ちていった。
Many old customs have been forgotten with the passage of time.