Actor without speaking role unusually (5)
I believe the answer is:
extra
'actor' is the definition.
(extra is a type of actor)
'without speaking role unusually' is the wordplay.
'without' becomes 'ex' (Latin).
'speaking role unusually' becomes 'tra' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ex'+'tra'='EXTRA'
Can you help me to learn more?
(Other definitions for extra that I've seen before include "Another" , "Left over" , "Ancillary" , "particularly" , "Bolt-on" .)