By the sound of it, I’ll row (5)
I believe the answer is:
'row' is the definition.
'by the sound of it i'll' is the wordplay.
'by the sound of it' shows a homophone (sound like).
'ill' is a homophone of 'AISLE'.
(Other definitions for aisle that I've seen before include "A key" , "Passageway between seating areas" , "channel" , "'Passage, gangway (5)'" , "Way between seat blocks" .)