What is the past participle of dirty?

Answer 1

Dirty is typically used as an adjective (i.e. He played in the mud and came out dirty), but as it does have a verbal form (i.e. The shoes were too clean, so we decided to dirty them up.) it can have a past participle.

Past Participle: Dirtied.

Answer 2

The past participle of "dirty" is "dirtied."