having the same meaning

The words "annoyed" and "irritated" are more or less synonymous. annoyed 和 irritated 两个词差不多是同义的。

If you say that one thing is synonymous with another, you mean that the two things are so closely connected in most people's minds that one suggests the other.

Oscar Wilde's name is synonymous with wit. 奥斯卡‧王尔德的名字成了机智幽默的同义语。