1) A laugh; fun; a good time.
2) To sleep rough, usually on somebody's couch or floor but can also mean on the streets.
3) To freeload, particularly while receiving state benefits such as the dole (Jobseeker's Allowance).
2) "Shit, I've missed the last bus home. Do you mind if I doss on your floor?"
3) "I quit my job and spent the whole summer dole dossing: just skateboarding all day and partying all night."
In Edinburgh for example, If Bob was to call his mate Tam a "Doss cunt", he would be using the term as an adjective to mean thick, useless, stupid.
If the term 'doss' is used in Perthsire, Angus, and the North East, then it is generallt intended to mean...Ace, Fantastic, shit-hot, etc..
"git a fuckin haud o yersel ye doss cunt!"
Did you see Liverpool in European Cup last night, that was pure doss!"