Two interesting Christianese terms from the streets are Jerusalem Slim and Nazareth Blacky, both of which are tramp-style nicknames for Jesus.
In the 1920s and later, tramps and hobos often went by nicknames. The nicknames often referred to the part of the country the tramp was from or something about about their physical appearance. You’ve probably heard of Minnesota Fats (a portly pool player). If a person was young, then they would incorporate “Kid” into their nickname, hence Billy the Kid and the Sundance Kid. (Tramps and outlaws and vagabonds are all part of the same extended family when it comes to both lifestyle and nicknaming conventions.)
When tramps wanted to talk about Jesus, they applied the same rules they knew. In the popular imagination, Jesus was a skinny wanderer who ended up in Jerusalem. Thus: Jerusalem Slim. Or, thinking of it another way, he was a dark-skinned (or dark-haired) guy born in Nazareth. Hence: Nazareth Blacky. By referring to Jesus using these nicknames, the hobos reinforced their own important ideas about aliases and privacy.
Here’s the definition for Jerusalem Slim as I have it so far, replete with several citations starting in the 1920s, when the lifestyle (and influence) of tramps and hobos was at its peak.
Jerusalem Slim n. [a nickname for Jesus patterned after the nicknaming conventions of hobos; Jerusalem ‘a city frequented by Jesus’ + Slim ‘an allusion to Jesus’s supposed slight frame due to his itinerant lifestyle’] ‹U.S. streets› Jesus Christ; a nickname for Jesus used by hobos, particularly those who were members or supporters of the Industrial Workers of the World (I.W.W.), a large labor union.
See also *Nazareth Blacky.
• 1921 poem published in I.W.W. publication, as cited in Bruns Knights of the Road: A Hobo History (1980) 23 : You call me Christ Jesus …/But I was a rebel called Jerusalem Slim. 1924 Pacific Reporter vol. 223 : The same witness was permitted to testify that … the members of the organization [the I.W.W.] refer to the Savior as “Jerusalem Slim.” 1946 in Fighting Words (1949) 225 : “This is the story of Jerusalem Slim,” Red said, slowly rolling himself a cigarette, his gaunt face staring at the floor intent on his story. “Jerusalem Slim,” he repeated, “and the Twelve Bindlestiffs.” 1990 Nelson Workers on the Waterfront: Seamen, Longshoremen, and Unionism in the 1930s 25 : In the realm of religion, the seaman was hardly noted for his piety or church membership. Many a sailor must have felt some kinship with the suffering of “Jerusalem Slim,” but he was likely to regard clergymen was “sky pilots” who directly or indirectly served the interests of the shipowners.
Nazareth Blacky n. [a nickname for Jesus patterned after the nicknaming conventions of hobos; Nazareth ‘Jesus’s city of origin’ + Blacky ‘an allusion to Jesus’s supposed dark/Mediterranean skin color’] ‹U.S. streets› Syn *Jerusalem Slim.
• 1996 Toelken The Dynamics of Folklore 72 : Some of the guys even had names for Jesus Christ, like Nazareth Blacky or Jerusalem Slim.