Went astray, shortly going round town in County Clare (5)
I believe the answer is:
ennis
'town in county clare' is the definition.
'went astray shortly going round' is the wordplay.
'went astray' becomes 'sinned'.
'shortly' means to remove the last letter.
'going round' says the letters should be written backwards.
'sinned' with its last letter taken away is 'sinne'.
'sinne' reversed gives 'ENNIS'.
(Other definitions for ennis that I've seen before include "World champ" , "place of Clare" , "somewhere in Ireland" , "County town of Co Clare, Ireland" , "our potential 1/4 Across [GOLD MEDALLIST] in 2012" .)