It's brilliant, being like Alfred! (5)
I believe the answer is:
great
'it's brilliant' is the definition.
(thesaurus)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for great that I've seen before include "Mum's dad's mum, for example" , "Chief - weighty" , "Brunel's third and last steamship" , "Important - splendid" , "Large; fine" .)