Sally is kind, that is evident (6)
I believe the answer is:
sortie
'sally' is the definition.
(I know that sally can be written as sortie)
'kind that is evident' is the wordplay.
I cannot quite understand how this works, but
'kind' could be 'sort' (synonyms) and 'sort' is located in the answer.
'that is' could be 'ie' (abbreviation for id est, 'that is' in Latin) and 'ie' is found within the answer.
No letters remain.
This explanation may well be incorrect...
'is' is the link.
Can you help me to learn more?
(Other definitions for sortie that I've seen before include "Short trip; attack" , "Operational flight by a bomber or fighter" , "Military foray" , "Military raid" , "Sally" .)