To Decay
To Die Out
intransitive verb, ichidan verb
くちる
腐る (くさる) To Rot
朽ちる (くちる) To Decay, To Die Out
衰える (おとろえる) To Decline, To Decay, To Become Weak, To Wither
枯れる (かれる) To Wither, To Die
A mouth 口 くち that's rude る will cause respect To Decay.