Lead role ultimately bagged in hit (5)
I believe the answer is:
leash
'lead' is the definition.
(synonyms)
'role ultimately bagged in hit' is the wordplay.
'ultimately' suggests the final letters.
'bagged in' is an insertion indicator.
'hit' becomes 'lash' (I've seen this before).
The final letter of 'role' is 'e'.
'e' put within 'lash' is 'LEASH'.
(Other definitions for leash that I've seen before include "Restraining strap for dog" , "Bind" , "A dog walker may use it" , "Strip for leading, a dog say" , "Rope or chain restraint" .)