Christmas, for example, in Ireland, for instance (6)
I believe the answer is:
island
'instance' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for island that I've seen before include "Christmas or Easter, perhaps?" , "Piece of land smaller than a continent" , "Land mass not bordering another" , "Boffin, Baffin or Bali, say" , "Man, maybe" .)