Living in centre of Southampton upset friend (7)
I believe the answer is:
animate
'living' is the definition.
(similar in meaning)
'in centre of southampton upset friend' is the wordplay.
'centre of' means to look at the middle letters.
'upset' says the letters should be written backwards.
'friend' becomes 'mate' (mate is a kind of friend).
The middle of 'southampton' is 'a'.
'in'+'a'='ina'
'ina' backwards is 'ani'.
'ani'+'mate'='ANIMATE'
(Other definitions for animate that I've seen before include "Spirited" , "Infuse with life" , "Liven up" , "Enliven, inject energy into" , "Enliven, alive" .)