Supply gin on the rocks popular during the Christmas season (8)

I believe the answer is:

stocking

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'supply' is the definition.
(stocking is a kind of supply)

I cannot understand how the rest of the clue works.

(Other definitions for stocking that I've seen before include "fireside D [DECORATION]" , "See 8" , "Item hung up at Christmas" , "a hang-up at Christmas?" , "White marking on the lower part of a horse's leg" .)

I've seen this clue in the Irish Times and the Irish Times (Crosaire).

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