By the sound of it, I’ll row (5)
I believe the answer is:
Here is my best explanation:
'row' is the definition.
'by the sound of it ill' is the subsidiary indication.
'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 "Supermarket feature", "Church passage", "part of theatre?", "Part of a church", "channel", "Passageway between blocks of seats", "Path between seats in church", "Supermarket passageway", "Extension of the nave in a church" and "Supermarket section".)