major-league

adjective

1. 1

   Of or pertaining to a major sports league; belonging to the professional level of a sport, such as US baseball.

2. 2

   Analogous in importance to a major league sports team.

   “Calatrava is a major league architect.”

3. 3

   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.”