Short part of better series (5)
I believe the answer is:
terse
'short' is the definition.
(terse can mean short or brusque)
'part of better series' is the wordplay.
'part of' indicates a hidden word.
'TERSE' is hidden within 'better series'.
(Other definitions for terse that I've seen before include "Brusque, concise" , "Abrupt, concise" , "Brief; abrupt" , "Short and sharp" , "Short, abrupt" .)