The grasses -- regularly cut short (5)
I believe the answer is:
terse
'short' is the definition.
('terse' can be a synonym of 'short')
'the grasses regularly cut' is the wordplay.
'regularly cut' indicates alternate letters.
'the'+'grasses'='thegrasses'
The alternating letters of 'thegrasses' are 'TERSE'.
(Other definitions for terse that I've seen before include "Short and to the point" , "Short and sharp" , "Sententious" , "Short, abrupt" , "Sparing with words; abrupt" .)