During the winter season it's short (5)
I believe the answer is:
terse
'short' is the definition.
('terse' can be a synonym of 'short')
'during the winter season it's' is the wordplay.
'during' indicates the answer is hidden within the clue.
'TERSE' is hidden within 'winter season ts'.
(Other definitions for terse that I've seen before include "Sententious" , "Of speech, short and pithy" , "Trees (anag.)" , "Short and succinct" , "Aphoristic" .)