Cock Robin initially rose to dance (7)
I believe the answer is:
rooster
'cock' is the definition.
(I know that cock can be written as rooster)
'robin initially rose to dance' is the wordplay.
'initially' indicates taking the first letters.
'dance' indicates anagramming the letters.
The first letter of 'robin' is 'r'.
'rose'+'to'='roseto'
'roseto' with letters rearranged gives 'ooster'.
'r'+'ooster'='ROOSTER'
(Other definitions for rooster that I've seen before include "Adult male chicken" , "Male hen" , "Adult male domestic fowl" , "Farmyard fowl" , "Male domestic fowl (US)" .)