Aim to secure new life in London suburb (7)
I believe the answer is:
enfield
'london suburb' is the definition.
(area of north London)
'aim to secure new life' is the wordplay.
'aim' becomes 'end' (both can mean a goal or purpose).
'to secure' indicates putting letters inside (inserted letters are secured inside).
'new' is an anagram indicator.
'life' is an anagram of 'fiel'.
'end' going around 'fiel' is 'ENFIELD'.
'in' acts as a link.
(Other definitions for enfield that I've seen before include "London suburb" , "Big centre" , "NE London borough" , "Feel din of Kildare town" , "North London borough" .)