If you say that one thing is synonymous with another, you mean that the two things are very closely associated with each other so that one suggests the other or one cannot exist without the other.
双语例句
例： Paris has always been synonymous with elegance, luxury and style.
巴黎与优雅、华贵和时尚一直是密不可分的。
例： In politics, power and popularity are not synonymous.
政治上，权力和声望并非同义。