A dodger, in this sense, is someone who dishonestly gets out of paying. A tax dodger hides money or lies so they pay less tax than they should. A fare dodger rides a bus or train without a ticket. The word is dodge + -er: a person who dodges, slipping away from a duty they ought to meet. It is not a compliment. Newspapers use it a lot. Though actually, dodge itself can be playful — you dodge a ball in a game — but a dodger of tax or fares is cheating, not playing. You can put another word in front to show what they avoid: tax dodger, fare dodger, and so on.