Secrecy the last resort? (7)
I believe the answer is:
stealth
'secrecy' is the definition.
(I've seen this before)
'the last resort?' is the wordplay.
'resort?' indicates anagramming the letters (I've seen 'resort' mean this).
'the'+'last'='thelast'
'thelast' anagrammed gives 'STEALTH'.
(Other definitions for stealth that I've seen before include "underhand dealing" , "Unseen machination" , "Kind of indirect tax" , "Furtive behaviour" , "Skill in furtive activity" .)