1) Boys of summer gp 2) Boys of summer org 3) Bud Selig is its commish 4) Club with bats 5) Cubs and White Sox org 6) Diamond organisation 7) Organisation for mariners 8) Orioles and Cardinals org 9) World Series org 
Short form for Major League Baseball, generally the association operating the two North American major professional baseball leagues such as the American League and the National League.