1952, short for jockstrap "supporter of the male genital organs," which also meant, in slang, "athletic male." Jock with the meaning "an athletic man" is from 1963, American English slang.
例文
1. When Jock woke up and found you gone he went crazy.
ジョックが目を覚ますと、あなたが行ってしまったことに気づき、彼は気が狂ってしまった。
2. Jock 's face had been suddenly drained of all colour.
ジョックの顔が急に白くなった。
3.What Jock had done was beyond my comprehension.
私はジョックのしたことを理解できません。
4. Jock paused for effect,his eyes glinting over his glass he took another drink.