1. most covered with dirt, mud, or unwanted matter; least clean
Usage: superlative form of dirty
2. most morally corrupt or dishonest
Usage: figurative use
3. most unfair or unsportsmanlike
Usage: informal

Examples

• His shoes were the dirtiest after working in the garden all day.
• The kitchen was the dirtiest room in the abandoned house.
• She accused him of playing the dirtiest tricks in politics.
• That was the dirtiest play I’ve ever seen in football.
• The dirtiest clothes went straight into the washing machine.
• He had the dirtiest hands after fixing the car engine.