This word has been used up and down the east coast since the early eighties. It is disputed whether the word evolved from the word "junk" or "joint". Origins are most likely in NY or Washington DC. It is used to denote any person place or thing.
Also pronounced in some regions as jawnk or jont all though the "k" or "t" at the end of the word is allmost always inaudabile. Hence the spelling here of jawn.
Hand me dat jawnk
She went to dat jawnk
I aint never seen dat jawnk before