'sports' refers to all sports. "I like playing sports, but I don't like watching others play sports." 'sport' can refer to a single sport. "This is how you play the sport of baseball. OR 'sport' can refer to doing something 'for fun'. "I read books for sport." "Hunting for sport is a favorite passtime of my family." When it is used to mean doing something for recreation, you will usually see it written as 'for sport'. Otherwise, it refers to a single sport.

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.