Natural home — this place, supported by National Trust (8)
I believe the answer is:
inherent
'natural' is the definition.
(I've seen this before)
'home this place supported by national trust' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'this place' becomes 'here' (here in this location).
'supported by' is a charade indicator (letters next to each other) (in a down clue, some letters hold up others).
'national trust' becomes 'nt'.
'in'+'here'+'nt'='INHERENT'
(Other definitions for inherent that I've seen before include "constitutional" , "Existing in something as a permanent attribute" , "essential" , "deep-rooted" , "Existing permanently in something" .)