Advance large target (4)
I believe the answer is:
lend
'advance' is the definition.
(I've seen this before)
'large target' is the wordplay.
'large' becomes 'l'.
'target' becomes 'end' (I've seen this before).
'l'+'end'='LEND'
(Other definitions for lend that I've seen before include "Impart" , "contribute" , "Advance, loan" , "Let someone borrow" , "Give (a quality) to" .)