As yet unused to peculiar-looking beard, nephew is gutted and negative at first (8)

'as yet unused' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'peculiar-looking beard nephew is gutted and negative at first' is the wordplay.
'peculiar looking' indicates anagramming the letters (I've seen this in other clues).
'is gutted' says to hollow out the word (remove centre letters) (to gut something is to remove its insides).
'and' says to put letters next to each other.
'at first' suggests taking the first letters.
'nephew' with its middle taken out is 'nw'.
The initial letter of 'negative' is 'n'.
'beard'+'nw'='beardnw'
'beardnw' put after 'n' is 'nbeardnw'.
'nbeardnw' is an anagram of 'BRANDNEW'.

'to' acts as a link.

Can you help me to learn more?