Emaciated cardinal goes on about cold city (7)
I believe the answer is:
scrawny
'emaciated' is the definition.
(I've seen this in another clue)
'cardinal goes on about cold city' is the wordplay.
'cardinal' becomes 'S' (South, a cardinal direction).
'goes on about cold' becomes 'craw' (I am not sure about this - if you are sure you should believe this answer much more).
'city' becomes 'ny' (short for New York).
's'+'craw'+'ny'='SCRAWNY'
Can you help me to learn more?
(Other definitions for scrawny that I've seen before include "Rawboned" , "Skin-and-bones" , "Being underweight" , "Thin and bony" , "Thin and scraggy" .)