Short bitter argument brings sadness (6)
I believe the answer is:
sorrow
'sadness' is the definition.
(I know that sadness can be written as sorrow)
'short bitter argument' is the wordplay.
'short' means to remove the last letter.
'bitter' becomes 'sore' (sore can mean bitter or resentful).
'argument' becomes 'row' (to row is to argue).
'sore' with its last letter taken away is 'sor'.
'sor'+'row'='SORROW'
'brings' is the link.
(Other definitions for sorrow that I've seen before include "Sadness; one magpie for it" , "Sadness,regret" , "'Sadness, grief (6)'" , "'One magpie for ..., two for joy (6)'" , "Deep sadness" .)