Heartless feline creating row (4)
I believe the answer is:
tier
'row' is the definition.
(a tier is a row of things)
'heartless feline' is the wordplay.
'heartless' suggests removing the centre.
'feline' becomes 'tiger' (tiger is a kind of feline).
'tiger' with its centre removed is 'TIER'.
'creating' is the link.
(Other definitions for tier that I've seen before include "Hierarchical level" , "Layer, rank" , "Rite (anag.)" , "Row in theatre" , "Person joining" .)