Old man given year to settle up (3)
I believe the answer is:
pay
'settle up' is the definition.
(I've seen this before)
'old man given year' is the wordplay.
'old man' becomes 'pa' (both can mean father).
'given' means one lot of letters go next to another.
'year' becomes 'y'.
'pa'+'y'='PAY'
'to' is the link.
(Other definitions for pay that I've seen before include "Remunerate" , "profitable" , "Hand over money for" , "Financial reward" , "Remuneration" .)