She’s a c-cat! (4)
I believe the answer is:
cleo
'she's' is the definition.
'a c-cat' is the wordplay.
'cat' becomes 'leo' ('lion' in Latin).
'c'+'leo'='CLEO'
(Other definitions for cleo that I've seen before include "She ruled" , "Ms Laine - one of the 14 films" , "Carry on -- (1964 film)" , "Woman" , "Dame Laine" .)