Early Miles was a standout player in the Negro Leagues back in the mid '30s and early (no pun intended) '40s, retiring in 1943 after a productive career. He held the all-time Negro League stolen base record with 1,986, leading many to believe "Early" was simply a nickname. He was also a great leadoff hitter, with a career .377 batting average. Often he scored the first run of the game early in the first inning, stealing second and third bases, then home plate. He moved to Philadelphia in 1944 and became addicted to crack. He overdosed by Pat's Cheesesteaks in January of 1946. Every time someone shouts "early!" not only are they paying homage to one of the Negro League's greatest, they are also just as excited as most were while watching his awesome play on the field.
"we are going to f*** you up, early!"
with other slang:
"who us?...word on bizz
as a greeting: