A feeling no one book reflects (7)
I believe the answer is:
emotion
'a feeling' is the definition.
(I know that emotion is a type of feeling)
'no one book reflects' is the wordplay.
'one' becomes 'I' (Roman numeral).
'book' becomes 'tome' (a tome is a book).
'reflects' shows that the letters should be reversed in order.
'no'+'i'+'tome'='noitome'
'noitome' backwards is 'EMOTION'.
(Other definitions for emotion that I've seen before include "Strong desire" , "Intuitive feeling" , "E.g. fear, hate etc." , "Mental agitation" , "Hatred or love, say" .)