One smear for one from Tonga, say (8)
I believe the answer is:
islander
'one from tonga say' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'one smear' is the wordplay.
'one' becomes 'i' (Roman numeral).
'smear' becomes 'slander' (synonyms).
'i'+'slander'='ISLANDER'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for islander that I've seen before include "End rails (anag)" , "Inhabitant of Man, for example" , "E.g. Shetland inhabitant" , "person from Cuba?" , "a Corsican, perhaps" .)