Left somewhat short (4)
I believe the answer is:
quit
'left' is the definition.
(I've seen this in other clues)
'somewhat short' is the wordplay.
'somewhat' becomes 'quite' (I've seen this before).
'short' means to remove the last letter.
'quite' with its final letter removed is 'QUIT'.
(Other definitions for quit that I've seen before include "Vacate" , "Depart, resign from" , "Go away from or abandon task" , "Cease" , "Pay off (a debt)" .)