With which to row (4)
I believe the answer is:
oars
'with which to row' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for oars that I've seen before include "Implements of propulsion on water" , "Henley sportsmen" , "Poles to propel a boat" , "Sculls" , "Indirectly, they make waves" .)