Scene stealer (3)
I believe the answer is:
ham
'scene stealer' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ham that I've seen before include "Gammon" , "An actor who overdoes it in meaty way" , "Meat served in sandwiches" , "Meat; radio operator" , "under twenty-eight [HIP]" .)