Original guy bored by literature mounted musical (7)
I believe the answer is:
matilda
'musical' is the definition.
Both the answer and definition are singular nouns.
Maybe you can see an association between them that I don't see?
'original guy bored by literature mounted' is the wordplay.
'original guy' becomes 'adam' (I have seen 'First guy' mean 'adam' so perhaps 'guy' could also mean 'adam'. I am not sure about the 'original' bit.).
'bored by' is an insertion indicator (inserted letters bore into the word).
'literature' becomes 'lit' (abbreviation).
'mounted' is a reversal indicator (in a down clue, letters mounted up).
'adam' placed around 'lit' is 'adlitam'.
'adlitam' backwards is 'MATILDA'.
Can you help me to learn more?
(Other definitions for matilda that I've seen before include "12th century English empress" , "She fought Stephen for the crown in twelth century England" , "She waltzes in Australian song" , "Novel by Roald Dahl; girl's name" , "Name of girl (who told such dreadful lies) - daughter of Henry I" .)