Major row (4)
I believe the answer is:
rank
This clue could be a double definition.
'major' is the first definition.
Both the answer and definition are adjectives. Perhaps they are linked in a way I don't understand?
'row' is the second definition.
(as in a taxi rank)
Can you help me to learn more?
(Other definitions for rank that I've seen before include "Status; foul" , "Noisome" , "Social standing; foul-smelling" , "Row, class" , "Position of seniority" .)