Green’s Dictionary of Slang

1. (US) an organ.

1911

L. Pound ‘A Second Word-List From Nebraska’ in DN III:vii 549: Some common cases of ‘back-formation,’ or ‘back-shortening,’ are: [...] org.

2. an organization.

1936		Esquire Sept. 160/3: The Joe Breen (Hays org) influence on pix.
1951		D.P. Mannix Sword-Swallower 105: ‘People just don’t understand Steve in this org,’ Billie told me.
1957		H. Simmons Corner Boy 91: He also had an org going. His org was solid.
1974		Maclean’s (Toronto) June 77: Inside the Toronto org, I saw one ceremony that might be construed as worship.
2016		Barer et al. Betrayal in Blue 135: NYPD’s massive size made for a large org chart too.