Brand new day, etc, for coward (7-3)
I believe the answer is:
scaredy-cat
'coward' is the definition.
(I've seen this before)
'brand new day etc' is the wordplay.
'brand' becomes 'scar' (I've seen this before).
'new' is an anagram indicator.
'day'+'etc'='dayetc'
'dayetc' anagrammed gives 'edycat'.
'scar'+'edycat'='SCAREDY-CAT'
'for' acts as a link.
(Other definitions for scaredy-cat that I've seen before include "Timid person (or feline?)" , "Coward" , "7 across" , "One easily frightened" , "Timid type" .)