Sailor's love for a DJ (4)

I believe the answer is:

jock

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'for a dj' is the definition.
(short for disc jockey)

I cannot understand how the rest of the clue works.

(Other definitions for jock that I've seen before include "American athlete -- Scottish soldier" , "Native unlikely to want him as MP" , "US athlete" .)

I've seen this clue in The Independent.

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