Actor shoots sailor (4,4)
I believe the answer is:
film star
'actor' is the definition.
(film star is a kind of actor)
'shoots sailor' is the wordplay.
'shoots' becomes 'films' ('film' can be a synonym of 'shoot').
'sailor' becomes 'tar' (tar is a kind of sailor).
'films'+'tar'='FILM-STAR'
(Other definitions for film star that I've seen before include "Saoirse Ronan or Colin Farrell, say" , "Cinema celebrity" , "'Matt Damon or Jennifer Lopez, say (4,4)'" , "Hollywood notable" , "Saoirse Ronan or Maureen O'Hara, say" .)