dirty 有「臟的」意思，但除此之外，dirty 作為形容詞還有更多含義。
dirty adj. （NOT HONEST）
unfair， dishonest， or unkind
She played a dirty trick on me by telling me Diane was having a party when she wasn‘t.
That‘s a dirty lie！
dirty adj. （NOT POLITE）
used to describe something that is connected with sex， in a way that many people think is offensive
a dirty magazine/movie/joke
You have a really dirty mind！
do sb‘s dirty work
to do something unpleasant or difficult for someone else who does not want to do it himself or herself
Tell her yourself - I‘m not going to do your dirty work for you.
do the dirty on sb
to behave unfairly towards someone， usually without their knowledge
He can‘t forgive her for doing the dirty on him and having an affair with his best friend.
give sb a dirty look
to look at someone in a disapproving way
He gave me a really dirty look.
to behave dishonestly， especially by cheating in a game
Don likes hockey， but he plays dirty.