Monstrous dog devours a knight (6)
I believe the answer is:
mutant
'monstrous' is the definition.
Although both the answer and definition are adjectives, I don't understand how one could define the other.
'dog devours a knight' is the wordplay.
'dog' becomes 'mutt' (mutt is a kind of dog).
'devours' is an insertion indicator (inserted letters are devoured).
'knight' becomes 'N' (chess abbreviation).
'a'+'n'='an'
'mutt' placed around 'an' is 'MUTANT'.
Can you help me to learn more?
(Other definitions for mutant that I've seen before include "Genetically changed form" , "Living thing that undergoes genetic change" , "Cell that carries an alteration of a gene" , "Organism that has diverged from type" , "Living thing that has undergone genetic change" .)