Beastly type chewed acorn, firm inside (7)
I believe the answer is:
raccoon
'beastly type' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'chewed acorn firm inside' is the wordplay.
'chewed' indicates an anagram.
'firm' becomes 'co' (a firm is a company).
'inside' is an insertion indicator.
'acorn' with letters rearranged gives 'racon'.
'racon' going around 'co' is 'RACCOON'.
Can you help me to learn more?
(Other definitions for raccoon that I've seen before include "Arboreal mammal" , "US nocturnal mammal" , "North American mammal with fur used for hats" , "Greyish-brown American mammal" , "American nocturnal mammal" .)