Rows hard, first to last (5)
I believe the answer is:
tiffs
'rows' is the definition.
(tiff is a kind of row)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for tiffs that I've seen before include "Huffs; squabbles" , "Small quarrels" , "Spats" , "Arguments" , "Petty quarrels" .)