One saint potentially from Tallinn (8)
I believe the answer is:
estonian
'tallinn' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'one saint potentially' is the wordplay.
'potentially' indicates anagramming the letters (letters have the potential to spell a new word).
'one'+'saint'='onesaint'
'onesaint' with letters rearranged gives 'ESTONIAN'.
'from' acts as a link.
Can you help me to learn more?
(Other definitions for estonian that I've seen before include "Eastern Europe" , "Baltic state native" , "Foreign" , "Baltic state national" , "Northern European" .)