Extract from screenwriter, seriously short (5)
I believe the answer is:
terse
'short' is the definition.
('terse' can be a synonym of 'short')
'extract from screenwriter seriously' is the wordplay.
'extract from' says the answer is hidden in the clue (I've seen this in other clues).
'TERSE' can be found hidden inside 'screenwriter seriously'.
(Other definitions for terse that I've seen before include "Sparing with words; abrupt" , "Brusque and curt" , "Crisply brief" , "Of speech, short and pithy" , "Curt among trees" .)