Fix guys drinks at the start (4)
I believe the answer is:
mend
'fix' is the definition.
(I know that fix can be written as mend)
'guys drinks at the start' is the wordplay.
'guys' becomes 'men' (guy can mean a man).
'at the start' suggests taking the first letters.
The initial letter of 'drinks' is 'd'.
'men'+'d'='MEND'
(Other definitions for mend that I've seen before include "Make improvements" , "Heal" , "Put right" , "Return to health; repair" , "Fix, repair" .)