Definition of "jock"

"You've heard of him?" "No." "Why, young fellah, where have you lived? Sir John Ballinger is the best gentleman jock in the north country."

1912, Arthur Conan Doyle, The Lost World […], London, New York, N.Y.: Hodder and Stoughton

'Cause all jocks ever think about is sports, all we ever think about is sex.

1984, Steve Zacharias, Jeff Buhai (screenplay), Revenge of the Nerds (motion picture), spoken by Lewis (Robert Carradine)

There was never a single listener protest or objection — the entire opposition to the content of the program came from a few jocks within the station.

1977 April 16, "Hartford Radio Show Axed", in Gay Community News, page 6, quoting Eric Gordon

As a teenager, I laid down the sword and decided I wanted to be a disc jockey. […] I'd sit outside the studio and watch with envy and admiration as the jocks performed in the small room on the other side of the soundproof window […]

2010, Stephen B. McSwain, The Enoch Factor: The Sacred Art of Knowing God, page 95

Thear's boan-idle nowbles, baht hahses an' lands, 'at al walk on a carpeted path, an' nivver do nowt wi' ther lily-white hands bud lift uther fowk's jock to ther maath.

1881, Ben Preston, Dialect and Other Poems‎, page 19

Hah's a growing lad to thrive baht jock?

1884, William Cudworth (of Bradford), Yorkshire Dialect and Character Sketches‎, page 15