Sally’s kind, extremely inventive (6)
I believe the answer is:
sortie
'sally's' is the definition.
(synonyms)
'kind extremely inventive' is the wordplay.
'kind' becomes 'sort' (synonyms).
'extremely' means to remove the middle letters (only the extremes of the word are used).
'inventive' with its centre taken out is 'ie'.
'sort'+'ie'='SORTIE'
(Other definitions for sortie that I've seen before include "Short trip; attack" , "Military manoeuvre" , "Sally" , "Short foray" , "Sudden attack by besieged troops" .)