Line round head of ginger cat (5)
I believe the answer is:
tiger
'cat' is the definition.
(tiger is a kind of cat)
'line round head of ginger' is the wordplay.
'line' becomes 'tier' (tier is a kind of line**).
'round' is an insertion indicator.
'head of' suggests taking the first letters.
The initial letter of 'ginger' is 'g'.
'tier' enclosing 'g' is 'TIGER'.
(Other definitions for tiger that I've seen before include "Large cat with black stripes" , "Endangered carnivore" , "Ferocious cat" , "dynamic economy" , "Striped quadruped" .)