Crossword Genius

Waste of time, what you may do to protect the environment? (7)

Ross

I believe the answer is:

useless

'waste of time' is the definition.
(something useless is a waste of time)

I can't explain the rest of the clue.

(Other definitions for useless that I've seen before include "Lacking in purpose" , "Fruitless" , "Poor" , "Without any worthwhile application" , "Unserviceable" .)

I've seen this clue in The Guardian.
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