Physical activity that is governed by a set of rules or customs and often engaged in competitively. A particular form of this activity. An activity involving physical exertion and skill that is governed by a set of rules or customs and often undertaken competitively. An active pastime; recreation. Mockery; jest: He made sport of his own looks. An object of mockery, jest, or play: treated our interests as sport. A joking mood or attitude: She made the remark in sport. One known for the manner of one's acceptance of rules, especially of a game, or of a difficult situation: a poor sport. Informal One who accepts rules or difficult situations well. Informal A pleasant companion: was a real sport during the trip. Informal A person who lives a jolly, extravagant life. Informal A gambler at sporting events. Biology An organism that shows a marked change from the normal type or parent stock, typically as a result of mutation. Maine See summercater. See Regional Note at summercater. Obsolete Amorous dalliance; lovemaking. To play or frolic. To joke or trifle. Biology To mutate. To display or show off: "His shoes sported elevated heels\u201d ( Truman Capote). Of, relating to, or appropriate for sports: sport fishing; sports equipment. Designed or appropriate for outdoor or informal wear: a sport shirt.