Waste what you've earned (6)

I believe the answer is:

desert

I'm a little stuck... Click here to teach me more about this clue!

'waste' is the definition.
(a desert may be described as a wasteland)

I don't understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for desert that I've seen before include "Abandon, desolate area" , "Sahara, Gobi, etc" , "Abandon in barren terrain" , "merit and a > quiet place" , "Sandy waste" .)

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app