Health centre son joined with father (3)
I believe the answer is:
spa
'health centre' is the definition.
(synonyms)
'son joined with father' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'joined with' is a charade indicator (letters next to each other).
'father' becomes 'pa' (pa can mean dad or father).
's'+'pa'='SPA'
(Other definitions for spa that I've seen before include "Watering hole" , "Healthy place" , "Health resort near a spring" , "Water source" , "Curative resort" .)