Place in Somerset, a colony to the west (6)
I believe the answer is:
locate
'place' is the definition.
(synonyms)
'in somerset a colony to the west' is the wordplay.
'in' indicates a hidden word.
'to the west' shows that the letters should be reversed in order (letters written right to left or 'east to west').
'etacol' is hidden in the letters of 'somerset a colony'.
'etacol' back-to-front is 'LOCATE'.
(Other definitions for locate that I've seen before include "Find, or establish in particular place" , "Put in place" , "Set in a particular place" , "Track down" , "Find; lay hands on" .)