Good will or ill, new year follows old (7)
I believe the answer is:
harmony
'good will' is the definition.
The definition and answer can be both human attributes as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'ill new year follows old' is the wordplay.
'ill' becomes 'harm' (as in doing people ill).
'new year' becomes 'ny' (abbreviation).
'follows' is a charade indicator (letters next to each other).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'ny' after 'o' is 'ony'.
'harm'+'ony'='HARMONY'
'or' acts as a link.
Can you help me to learn more?
(Other definitions for harmony that I've seen before include "Mellifluous sound" , "Accord" , "Pleasing blend of sounds" , "Mutual rapport" , "Source of universe for Dryden" .)