Goat maybe scratching head, say (5)
I believe the answer is:
utter
'say' is the definition.
(to utter something is to say or speak it)
'goat maybe scratching head' is the wordplay.
'goat maybe' becomes 'butter' (animal that butts).
'scratching head' means to remove the first letter (the word's head is removed).
'butter' with its initial letter removed is 'UTTER'.
(Other definitions for utter that I've seen before include "Circulate" , "Complete madman" , "Speak in absolute way" , "Make sounds (but not necessarily words)" , "talk" .)