Aimlessly wander where seas are dry (4)

I believe the answer is:

moon

I believe this clue is a double definition.

'aimlessly wander' is the first definition.

'where seas are dry' is the second definition.
(sea of tranquility etc.)

(Other definitions for moon that I've seen before include "Expose one's buttocks" , "Show Bottom!" , "Remove boxers, maybe" , "Titan, perhaps" , "Where Armstrong stood" .)

I've seen this clue in The Guardian.

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