Escort stranger routed round part of New England (8)
I believe the answer is:
outrider
'escort' is the definition.
(I know that outrider is a type of escort)
'stranger routed round part of new england' is the wordplay.
'stranger' indicates anagramming the letters.
'round' means one lot of letters goes inside another.
'part of new england' becomes 'ri' (I can't justify this - if you can you should give a lot more credence to this answer).
'routed' with letters rearranged gives 'outder'.
'outder' enclosing 'ri' is 'OUTRIDER'.
(Other definitions for outrider that I've seen before include "As far as" , "(Motorcade) guard on motorcycle" , "Motorcade escort" .)