Tempted, aim to retain the Yorkshire reserve (7)
I believe the answer is:
enticed
'tempted' is the definition.
('entice' can be a synonym of 'tempt')
'aim to retain the yorkshire reserve' is the wordplay.
'aim' becomes 'end' (both can mean a goal or purpose).
'to retain' means one lot of letters goes inside another.
'the yorkshire' becomes 't' (Northern English pronunciation of 'the').
'reserve' becomes 'ice ' (both can mean aloofness).
't'+'ice'='tice'
'end' placed around 'tice' is 'ENTICED'.
(Other definitions for enticed that I've seen before include "Persuaded with attractive offer" , "Tempted, lured" , "were seductive" , "Given inducement" .)