Regret briefly stinging argument (6)

I believe the answer is:

sorrow

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'regret' is the definition.
(I know that regret can be written as sorrow)

'briefly stinging argument' is the wordplay.
'briefly stinging' becomes 'sor' (I can't justify this - if you can you should believe this answer much more).
'argument' becomes 'row' (to row is to argue).
'sor'+'row'='SORROW'

Can you help me to learn more?

(Other definitions for sorrow that I've seen before include "trial?" , "Unhappiness" , "Woe" , "Expression of grief" , "Shakespeare: ''Parting is such sweet . . . . . .'' (6)" .)

I've seen this clue in The Irish Times.

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