Bruce Willis film (2 wds.) (7)
(Other definitions for diehard that I've seen before include "One strongly opposed to change" , "traditionalist" , "Hire dad (anag) - one who sticks to traditional views" , "Person who resists change" , "Obstinately conservative" .)
'bruce willis film' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for die hard that I've seen before include "missing the old ways" , "movie?" , "Traditionalist" , "Conservative" , "Reactionary" .)