Given illumination by our setter? (6)
I believe the answer is:
sunlit
'given illumination' is the definition.
The answer and definition are not the same part of speech. However, adjectives and past participle verbs can sometimes mean the same thing.
'by our setter?' is the wordplay.
'by' means one lot of letters go next to another.
'our' becomes 'lit' (I can't justify this - if you can you should give a lot more credence to this answer).
'setter?' becomes 'sun' (the sun sets every day).
'lit' put after 'sun' is 'SUNLIT'.
(Other definitions for sunlit that I've seen before include "Bright with solar illumination" , "Brightly illuminated" , "Illuminated from 93,000,000 miles away" , "Unclouded" , "facilitating one's vision, naturally" .)