Curt, abrupt (5)
I believe the answer is:
terse
This clue is a double definition.
'curt' is the first definition.
(I know that curt can be written as terse)
'abrupt' is the second definition.
(I've seen this before)
(Other definitions for terse that I've seen before include "Trees (anag.)" , "Crisp and brief" , "Briefly expressed" , "Aphoristic" , "Pithy among trees" .)