An association of sports teams which plays at the highest skill level of its sport, especially Major League Baseball.
(usually in plural or attributive) The highest level of competition in a field of endeavor.
You can't be so casual. You're in the major leagues now.
Of or pertaining to a major sports league; belonging to the professional level of a sport, such as US baseball.
Analogous in importance to a major league sports team.
Calatrava is a major league architect.
Serious, high-level; significant
Bill accidentally faxed sensitive documents to our competitors, and such a major league mess-up could only be dealt with by firing Bill.