Sting's playing Spain (5)
I believe the answer is:
pains
'sting's' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'playing spain' is the wordplay.
'playing' is an anagram indicator.
'spain' with letters rearranged gives 'PAINS'.
Can you help me to learn more?
(Other definitions for pains that I've seen before include "Great care taken" , "Symptoms of hurt or disease" , "Labour" , "Nice bakery's production" , "Aches" .)