歯は向むかう

godan verb (-u), intransitive verb

defy; oppose; rise against; turn on

Describes actively resisting or rebelling against a stronger opponent, authority, or expected behavior. Often used in negative or prohibitive expressions like 歯向かうな (don't defy).

• 部ぶ下かが上じょう司しに歯は向むかうなんて、めったにないことだ。

  It's rare for a subordinate to defy their boss.

• あの犬いぬは飼かい主ぬしにさえ歯は向むかうことがある。

  That dog sometimes even turns on its owner.