Bungling players initially employed in popular film (5)
I believe the answer is:
inept
'bungling' is the definition.
(synonyms)
'players initially employed in popular film' is the wordplay.
'initially' says to take the initial letters.
'employed in' means one lot of letters goes inside another.
'popular' becomes 'in' ('in' can mean trendy).
'film' becomes 'ET' (E.T. the Extra-Terrestrial).
The first letter of 'players' is 'p'.
'in'+'et'='inet'
'p' going into 'inet' is 'INEPT'.
(Other definitions for inept that I've seen before include "Hopelessly incapable" , "lacks skill" , "Awkward, clumsy" , "Ham-fisted" , "Incompetent and ineffectual" .)