Scarcity has 500 leaving planet (5)

I believe the answer is:

earth

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'planet' is the definition.
(Earth is an example)

I cannot understand how the remainder of the clue works.

(Other definitions for earth that I've seen before include "Fox's or badger's lair" , "Terrestrial sphere" , "Land" , "Soil; planet" , "Where some creatures live" .)

I've seen this clue in The Sun.

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