Two birds seen at dawn (8)
I believe the answer is:
cockcrow
'at dawn' is the definition.
'cockcrow' can be an answer for 'dawn' (synonyms). I am not sure about the 'at' bit.
'two birds' is the wordplay.
'two birds' means two substitutions for 'bird'.
'bird' becomes 'cock' (cock is a kind of bird).
'bird' becomes 'crow'.
'cock'+'crow'='COCKCROW'
'seen' is the link.
Can you help me to learn more?
(Other definitions for cockcrow that I've seen before include "first thing?" , "Dawn as signalled by rooster" , "Break of day" , "Dawn as signalled by farmyard fowl (4.4)" , "Dawn as announced by farmyard fowl" .)