Variety theatre before end could have been placed in danger (10)
I believe the answer is:
threatened
'in danger' is the definition.
(thesaurus)
'variety theatre before end could have been placed' is the wordplay.
'variety' indicates anagramming the letters.
'before' means one lot of letters go next to another.
'end' indicates one should take the final letters.
'placed' is an anagram indicator (placing the letters).
The final letters of 'could have been' are 'den'.
'theatre' anagrammed gives 'threate'.
'den' is an anagram of 'ned'.
'threate'+'ned'='THREATENED'
(Other definitions for threatened that I've seen before include "Facing danger" , "Put at risk, endangered" , "was imminent" , "potentially facing extinction" , "browbeaten" .)