Cover silencer, gun parts (6)
I believe the answer is:
sheath
'cover' is the definition.
(I know that sheath is a type of cover)
'silencer gun parts' is the wordplay.
'silencer' becomes 'sh' ('sh' is used to demand silence).
'gun parts' becomes 'eath' (I can't justify this - if you can you should give a lot more credence to this answer).
'sh'+'eath'='SHEATH'
Can you help me to learn more?
(Other definitions for sheath that I've seen before include "case for weapon" , "Sword covering" , "Protective cover" , "Protective case for a knife or sword" , "Holder for a dagger" .)