Allows senior relative time with son (6)
I believe the answer is:
grants
'allows' is the definition.
('grant' can be a synonym of 'allow')
'senior relative time with son' is the wordplay.
'senior relative' becomes 'gran' (I've seen this in other clues**).
'time' becomes 't'.
'with' says to put letters next to each other.
'son' becomes 's'.
'gran'+'t'+'s'='GRANTS'
(Other definitions for grants that I've seen before include "Bestows or concedes" , "Allows as a privilege or transfers legally" , "'Subsidies, monetary aid (6)'" , "Donations or subsidies" , "Gives formally or allows as privilege" .)