Five meanings/definitions for "sport"
1. Sport, countable noun = each individual sport
Example: Rugby is a team sport.
Example: Rugby and soccer are team sports.
2. "Sport", uncountable noun = generic noun for physical activity
Example: I used to play a lot of sport.
3. Sports, noun as modifier
Example: We shall build a sports centre with his donation.
4. Sport (a person), countable noun = a person who behaves in a good/bad way in a trying situation
Example: He was a good sport and joined us on our heritage trip even though he was not particularly interested in heritage exploration.
5. Sport, uncountable noun = pleasure to be had from fishing, shooting or hunting
Example: There is good sport to be had on the duke's Norfolk estate.