Mild distinction about island plague (8)
I believe the answer is:
nuisance
'plague' is the definition.
(thesaurus)
'mild distinction about island' is the wordplay.
'mild distinction' becomes 'nuance' (I have seen 'Fine distinction' mean 'nuance' so perhaps 'distinction' could also mean 'nuance'. I am not sure about the 'mild' bit.).
'about' means one lot of letters goes inside another.
'island' becomes 'is' (abbreviation).
'nuance' going around 'is' is 'NUISANCE'.
Can you help me to learn more?
(Other definitions for nuisance that I've seen before include "Annoying person/thing" , "See 16" , "Pest, pain in the neck" , "Bothersome pest" , "Source of annoyance or aggravation" .)