An end-of-season sports event happens at the end of a season (= the part of a year in which a sport is played).

the end-of-season play-offs 季后赛

relating to the end of a period of time when particular clothes, products, etc. are sold in shops

Prices are reduced by up to 75 percent in our end-of-season sale. 在过季甩卖中价格可低至二五折。

The store sells end-of-season stock at heavily discounted prices. 这家商店以跳楼价甩卖过季存货。