Meaning of “dirty” - Learner’s Dictionary

dirty

adjective us uk /ˈdɜːti/
Extra Examples
He's left dirty marks all over the carpet.You might get dirty so wear some old clothes.The trains were noisy, dirty, and unreliable.The water was dirty and unsafe to drink.There was a pile of dirty clothes on the floor.
NOT CLEAN

A2 not clean:

dirty clothes
dirty dishes
OFFENSIVE

talking about sex in a way that some people find offensive:

dirty books/jokes
DISHONEST

dishonest or unfair:

a dirty business
→ See also do sb's dirty work
HARMFUL

containing dangerous substances that may be harmful to the environment:

dirty air

(Definition of “dirty adjective” from the Cambridge Learner’s Dictionary © Cambridge University Press)