Blades appearing when people have a row (4)
I believe the answer is:
oars
'appearing when people have a row' is the definition.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for oars that I've seen before include "Implements of propulsion on water" , "Henley sportsmen" , "These could make you row" , "Paddles" , "Implements to propel a boat" .)