Sign from ensemble missed (6)
I believe the answer is:
emblem
'sign' is the definition.
(I know that emblem is a type of symbols)
'from ensemble missed' is the wordplay.
'from' indicates a hidden word.
'EMBLEM' is hidden in the letters of 'ensemble missed'.
(Other definitions for emblem that I've seen before include "Symbol, device that represents something" , "Symbol, representative device" , "Typifying symbol" , "Crest or symbol" , "Symbol, representing a country say" .)