Hint about one’s pain (8)
I believe the answer is:
nuisance
'pain' is the definition.
(I know that nuisance is a type of pain)
'hint about one's' is the wordplay.
'hint' becomes 'nuance' (I've seen this in another clue).
'about' means one lot of letters goes inside another.
'one's' becomes 'i's' (Roman numeral).
'nuance' placed around 'is' is 'NUISANCE'.
(Other definitions for nuisance that I've seen before include "One causing annoyance" , "Pest, pain in the neck" , "Annoying or troublesome person or thing" , "Irritant or botheration" , "See 16" .)