Green’s Dictionary of Slang

1. anywhere a vagrant, homeless person finds to sleep, such as a cardboard box, doorway etc.

1977

Family Radio 6 TV 23 Jan. 18: I was quickly introduced to the language of their world beyond the fringes of society. They aren’t hoboes, they are outies, and their domain is the outers. I never learned whether this was an abbreviation for outside, out of luck, out of respectability or a combination of all these ... Two newcomers to the outers .. had been sleeping in parking garages, bus-shelters and behind bushes for only five weeks. [Ibid.] 19: If they have one philosophy in common, it is this ... ‘Anything, but anything, is better than the outers’ ... Moral standards have no place on the outers... A lady shouldn’t sleep on the outers [DSAE].

2. a homeless person.

1985

B. Simon ‘Outers’ Born in the RSA (1997) 84: You take him to the Salvation Army [...] You stay with all the outers there.