Creature Geordie’s mother is going to, as we hear (6)
I believe the answer is:
mammal
'creature' is the definition.
(I know that mammal is a type of craniate)
'geordie's mother is going to as we hear' is the wordplay.
'geordie's mother' becomes 'mam' (Geordie or Newcastle version of 'mum').
'is going to' is a charade indicator (letters next to each other).
'as we hear' becomes 'mal' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'mam'+'mal'='MAMMAL'
(Other definitions for mammal that I've seen before include "Creature like man" , "Suckling animal" , "Animal that nourishes its young with milk" , "warm-blooded beast" , "Whale, for example" .)