Row of crop marks (6)
I believe the answer is:
racket
'row' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for racket that I've seen before include "loud din" , "Lot of noise, or tennis bat" , "Light bat" , "Din - strung bat" , "Din of the fraudulent moneymaking activity" .)