Mountain that looks grand in Eire, possibly (5)
I believe the answer is:
Here is my best explanation:
'mountain that looks' is the definition.
'eiger' can be an answer for 'mountain' (Swiss mountain). I'm not sure about the rest of the definition.
'grand in eire possibly' is the wordplay.
'grand' becomes 'g' ('G' can be a synonym of 'grand').
'in' means one lot of letters goes inside another.
'possibly' indicates an anagram.
'eire' anagrammed gives 'eier'.
'g' inserted within 'eier' is 'EIGER'.
Can you help me to learn more?