Initially sceptical old man in health resort (3)
I believe the answer is:
spa
'health resort' is the definition.
(spa can mean a health resort)
'initially sceptical old man' is the wordplay.
'initially' suggests taking the first letters.
'old man' becomes 'pa' (both can mean father).
The first letter of 'sceptical' is 's'.
's'+'pa'='SPA'
'in' is the link.
(Other definitions for spa that I've seen before include "town in Belgium" , "Resort with mineral water spring" , "hydro" , "Watering place" , "A curative mineral spring, or place with one" .)