Cry as cadet cooked chicken (7-3)
I believe the answer is:
scaredy-cat
'chicken' is the definition.
(I've seen this before)
'cry as cadet cooked' is the wordplay.
'cooked' indicates an anagram (letters cooked into a new form).
'cry'+'as'+'cadet'='cryascadet'
'cryascadet' with letters rearranged gives 'SCAREDY-CAT'.
(Other definitions for scaredy-cat that I've seen before include "Timid person (or feline?)" , "Coward" , "One easily frightened" , "7 across" , "Timid type" .)