The phrase "championship season" refers to a period of time in sports when teams or individuals compete against each other to win a championship or a title. Full definition
I have a pretty good idea who will win the national championship this season. (sbnation.com)
There are just 18 holes left in golf's major championship season. (sbnation.com)
But I am sure his personal quest comes first rather than the fans or success so lets just gear up for another 4th place championship season. (justarsenal.com)