Green’s Dictionary of Slang

outside adj.

[i.e. outside the primary relationships or the (fig.) house]

1. (US black, illegitimate, extra-marital; thus W.I.) outside daughter/son, outside kid/child, an illegitimate child; outside man, a woman’s lover; outside woman, a man’s lover.

[UK]‘Walter’ My Secret Life (1966) IV 795: French women don’t see much harm in an outside fuck or so.
[US]Lovie Austin ‘Barrel House Blues’ 🎵 Papa likes his bourbon, mama likes her gin / Papa likes his outside women, mama likes outside men.
[WI]A. Durie One Jamaica Gal 12: Her grandfather, father, and husband had all produced ‘outside’ families with comely brown paramours.
[US]A. Lomax Mister Jelly Roll (1952) 35: Mabe some of us is ‘outside’ children, because I don’t know for sure that Mama was really married to Jelly’s daddy or to mine.
[US]Brownie McGhee ‘I’m a Black Woman’s Man’ 🎵 I’m crazy ’bout my whiskey, crazy ’bout my gin But you know a yellow woman is crazy ’bout outside men.
[WI]L. Bennett ‘Jamaica Patoah’ in Jam. Dialect Poems 121: Leah fadah outside darter son / Wey dem call knock-knee Joe.
Dan Burley ‘Back Door Stuff’ 27 Nov. [synd. col.] His ‘quiet little wife’ has a list, courtesy of the gumshoe Dept., [...] of all the outside women he’s chasing.
[WI] (ref. to 1940s) L. Bennett Jamaica Labrish 223: outside daughter, son, child. illegitimate daughter, son, child of a married person.
[US]The Temptations ‘Papa Was a Rolling Stone’ 🎵 Papa had three outside children and another wife.
[US]J.L. Gwaltney Drylongso xvi: outside – illegitimate.
[US]J. Ellroy Suicide Hill 135: Sex the least likely [i.e. motivation for crime] , because they've got the outside stuff going.
C. Angier Jean Rhys (1992) 357: Her ‘outside’ relations, Owen’s children, came to see her.
[US]B. Gifford Sinaloa Story 171: What do you suppose Heaven be up to with that outside man [...] I mean, she dug Hernando.
[UK]Indep. Rev. 13 Aug. 13: The absent father [...] screwed around, fathered ‘outside’ children.
[US]R. Gordon Can’t Be Satisfied 140: ‘They got along okay but it was a lot of friction because of outside women’.
[US]S.A. Crosby Razorblade Tears 177: ‘He had a bunch of outside children’.

2. (US black) of someone considered ‘outside’ one’s friends or gang.

[US]Davis & Dollard Children of Bondage 37: [of beating] She put River Side boys ‘on the spot’ by leading them into traps and whistling for her gang of boys [...] who broke street lights so that they could beat up ‘outside’ boys.

SE in slang uses

In compounds

outside job (n.) [job n.2 (1a)]

a crime committed in a house etc. by a person not connected or associated with the household or building concerned.

[US]G. Henderson Keys to Crookdom 11: The prison authorities announced that it was an ‘outside’ job.
[UK]Guardian 14 Sept. 🌐 I am glad that all staff and officials have been cleared by the inquiry of using the information. I am very concerned about the lack of security and will be conducting an urgent review. It could have been an outside job.
outside money (n.)

(US) money earned outside one’s primary/official job.

[US]F. Brown Madball (2019) 174: Trixie had saved her money. Her outside money [...] every dollar she could make on the side, after hours, selling what all men wanted.
outside pal (n.) (also outside partner) [pal n. (1)]

(UK Und.) a lookout for a gang of thieves.

[US]Matsell Vocabulum.
[US]Nat. Police Gaz. (NY) 7 Sept. n.p.: Jim Colbert, their outside partner, furnished them with the ‘queer’ to play with a greenhorn.
outside work (n.)

(US und.) criminal work undertaken for others than the gang to whom one belongs.

[US]S.A. Crosby Razorblade Tears 113: ‘‘They definitely have taken some outside work [...] they done a fair bit for Chuly’.