Oarsman having argument with hesitation (5)
I believe the answer is:
rower
'oarsman' is the definition.
(synonyms)
'argument with hesitation' is the wordplay.
'argument' becomes 'row' (to row is to argue).
'with' is a charade indicator (letters next to each other).
'hesitation' becomes 'er' (sound used when hesitating).
'row'+'er'='ROWER'
'having' acts as a link.
(Other definitions for rower that I've seen before include "Might one argue" , "Sportsperson" , "crew member, perhaps" , "Person using 9" , "Oarswoman or oarsman" .)