Here, I'll make it simple. This is from the Dictionary.
sport (spôrt, sprt)
(Sports, Games, Clothing, Regional)
a. Physical activity that is governed by a set of rules or customs and often engaged in competitively.
b. A particular form of this activity.
2. An activity involving physical exertion and skill that is governed by a set of rules or customs and often undertaken competitively.
3. An active pastime; recreation.
a. Mockery; jest: He made sport of his own looks.
b. An object of mockery, jest, or play: treated our interests as sport.
c. A joking mood or attitude: She made the remark in sport.
a. One known for the manner of one's acceptance of rules, especially of a game, or of a difficult situation: a poor sport.
b. Informal One who accepts rules or difficult situations well.
c. Informal A pleasant companion: was a real sport during the trip.
a. A person who lives a jolly, extravagant life.
b. A gambler at sporting events.
7. Biology An organism that shows a marked change from the normal type or parent stock, typically as a result of mutation.
8. Maine See summercater. See Regional Note at summercater.
9. Obsolete Amorous dalliance; lovemaking.
v. sport·ed, sport·ing, sports
1. To play or frolic.
2. To joke or trifle.
3. Biology To mutate.
To display or show off: "His shoes sported elevated heels" Truman Capote.
adj. or sports
1. Of, relating to, or appropriate for sports: sport fishing; sports equipment.
2. Designed or appropriate for outdoor or informal wear: a sport shirt.
Hows that for you "sport"
There is alot there I never knew to be "sport" It looks to me by definition that R/C is a sport.