Shy, cut short the argument (5)
I believe the answer is:
throw
'shy' is the definition.
(thesaurus)
'cut short the argument' is the wordplay.
'cut short' means to remove the last letter.
'argument' becomes 'row' (to row is to argue).
'the' with its last letter taken away is 'th'.
'th'+'row'='THROW'
(Other definitions for throw that I've seen before include "Confuse - cast" , "Sling" , "Cast, hurl" , "Make a pot" , "Try to lose" .)