The kingdom of nature, almost (5)
I believe the answer is:
realm
'the kingdom' is the definition.
(kingdom is a type of country or realm)
'of nature almost' is the wordplay.
'of' indicates the answer is hidden within the clue.
'REALM' can be found hidden inside 'nature almost'.
(Other definitions for realm that I've seen before include "where ruler holds sway?" , "King's domain" , "World" , "Dominion" , "Peers are possessed by this" .)