Row or level (4)
I believe the answer is:
tier
I believe this clue is a double definition.
'row' is the first definition.
(a tier is a row of things)
'level' is the second definition.
(synonyms)
(Other definitions for tier that I've seen before include "Level - layer" , "Rite (anag.)" , "Storey" , "Person joining" , "Rite about layer" .)