Acts to secure son's meals (6)
I believe the answer is:
feasts
'meals' is the definition.
(feast is a kind of meal)
'acts to secure son's' is the wordplay.
'acts' becomes 'feats' (feats are heroic or impressive acts).
'to secure' indicates putting letters inside (inserted letters are secured inside).
'feats' enclosing 's' is 'FEASTS'.
(Other definitions for feasts that I've seen before include "'Ceremonial, elaborate meals (6)'" , "religious celebrations" , "eats well" , "Large rich meals" , "Banquets or celebratory days" .)