To perish; to be destroyed; to go extinct — an intransitive verb meaning to fall into ruin or cease to exist (applies to nations, species, civilizations, etc.).
その古い王国は戦争によって滅びた。
That ancient kingdom perished because of war.
小さな種は環境変化で滅びることがある。
Small species can become extinct due to environmental change.
誤った政策が国を滅びに導いた。
Wrong policies led the country to ruin.