shì​rú​shuǐ​huǒ

mutually incompatible

Senses

势如水火/ 勢如水火 shì​rú​shuǐ​huǒ mutually incompatible

in a state like water and fire; used to describe a situation where two parties are completely incompatible, intensely hostile, or at daggers drawn

References

antonym 亲如手足/親如手足 势如水火/勢如水火