PREFIX
(加在以字母r开头的单词前构成反义词)表示“不”，“非”
Ir- is added to words that begin with the letter 'r' to form words with the opposite meaning.
例句
His behaviour was becoming increasingly irrational.
他的行为变得越来越不理智了。
...its mixture of satirical wit, irreverence and spontaneity.
它融讽刺、机智、不敬、率真于一体