Evolving from combination of "janky" and "sketch-balls" (which comes from, and has similar meaning to "sketchy"). An adjective describing something below standard, shady, or all around questionable. Can refer to behavior or an object.
1.) That hooker pulled a jankmo-balls move and gave me herpes and didn't even have the courtesy to tell me.
2.) My jankmo-balls '84 Toyota Camry is a dirty-ass hoopty that smells like dead rat.