Food locked up (7)

I believe the answer is:

dessert

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'food' is the definition.
(dessert is a kind of food)

I cannot understand how the rest of the clue works.

(Other definitions for dessert that I've seen before include "Charlotte maybe" , "Sweet, last course of a meal" , "Fool possibly" , "Pudding, sweet" , "End of meal" .)

I've seen this clue in The Globe and Mail.

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