(idiomatic) to leave or get out (of anywhere) at once
Origin
The phrase is a reference to Dodge City, Kansas. Dodge City was the setting of innumerable Wild-West movies and books and, most prominently, the CBS-TV series Gunsmoke, which ran from 1955 to 1975. After being defeated by the good guys, bad men might stereotypically be commanded to "get the hell out of Dodge." The transferred sense, 'to leave or get out (of anywhere) at once', arose in the mid-1960s, when it was recorded in the slang of youth gangs, and became common by the 1970s.