From eastern Ireland to the west, uncannily scary? (5)
I believe the answer is:
eerie
'uncannily scary?' is the definition.
'eerie' can be an answer for 'scary?' (I've seen this in another clue). I'm not sure about the 'uncannily' bit.
'from eastern ireland to the west' is the wordplay.
'from' becomes 'e' (I am not sure about this - if you are sure you should believe this answer much more).
'eastern' becomes 'e'.
'ireland' becomes 'ire' (abbreviation).
'to the west' is a reversal indicator (letters written right to left or 'east to west').
'e'+'ire'='eire'
'eire' written backwards gives 'erie'.
'e'+'erie'='EERIE'
Can you help me to learn more?
(Other definitions for eerie that I've seen before include "Strange, unusual" , "Strange, frightening" , "Weird, uncanny" , "Unnatural" , "Uncannily strange" .)