Libertine employed in the garden? (4)

I believe the answer is:

rake

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'libertine' is the definition.
(I know that rake is a type of libertine)

I can't explain the rest of the clue.

(Other definitions for rake that I've seen before include "Scrape" , "Dissolute man of fashion" , "Progress was visualised for one" , "Garden tool for a dissolute fellow" , "Garden tool or loose fellow" .)

I've seen this clue in The Sun.

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