Part of the fair is held in the Emerald Isle (5)
I believe the answer is:
irish
'the emerald isle' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'part of the fair is held' is the wordplay.
'part of' indicates the answer is hidden within the clue.
'IRISH' is hidden within 'fair is held'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for irish that I've seen before include "Joyce was" , "From Galway, say" , "Hibernian -- breed of 4" , "One setter" , "race" .)