Gentle sort (4)
I believe the answer is:
kind
I believe this clue is a double definition.
'gentle' is the first definition.
(I've seen this before)
'sort' is the second definition.
('kind' can be a synonym of 'sort')
(Other definitions for kind that I've seen before include "Gracious" , "style" , "Generous - type" , "Type; good-hearted" , "Generous - sort" .)