Not a talking bird left — so-called! (7)
I believe the answer is:
nominal
'so-called' is the definition.
(I've seen this before)
'not a talking bird left' is the wordplay.
'not' becomes 'no' (negative).
'a talking bird' becomes 'mina' (bird which can imitate human speech).
'left' becomes 'l' (common abbreviation).
'no'+'mina'+'l'='NOMINAL'
(Other definitions for nominal that I've seen before include "Ostensible" , "unreal" , "Trivial" , "Ironical understatement (gram mar.)" , "Existing in name only" .)