约定俗成

yuēdìngsúchéng

HSK 7

约定俗成 — yuēdìngsúchéng

1. established by common usage; a convention that has developed by custom

   许多语言现象是约定俗成，而不是严格的规则。 xǔduō yǔyán xiànxiàng shì yuēdìngsúchéng ér búshì yángé de guīzé — Many linguistic phenomena are conventions established by usage, not strict rules.