Somewhat irrational loathing for Scottish town (5)
I believe the answer is:
alloa
'scottish town' is the definition.
(Alloa is a town in Scotland)
'somewhat irrational loathing for' is the wordplay.
'somewhat' indicates the answer is hidden within the clue.
'ALLOA' is hidden in the letters of 'irrational loathing for'.
(Other definitions for alloa that I've seen before include "Town built" , "Town near Stirling" , "place in Scotland" , "Athletic club" , "possible cup opponent" .)