Flightless birds of cold regions (8)
I believe the answer is:
penguins
'flightless birds of cold regions' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for penguins that I've seen before include "E.g. Kings and Emperors" , "Flightless sea-birds" , "books" , "Flightless birds of Antarctic regions" , "Flightless birds of cold regions" .)