Novel morphs into an elegant description of classical mechanics (9)
I believe the answer is:
newtonian
'mechanics' is the definition.
(Newtonian mechanics is an example)
'novel morphs into an' is the wordplay.
'novel' becomes 'new' (synonyms).
'morphs' indicates an anagram (I've seen 'morph' mean this (the letters morph into a new form)).
'into' is an anagram of 'toni'.
'new'+'toni'+'an'='NEWTONIAN'
'elegant description of classical' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for newtonian that I've seen before include "such a telescope?" , "Relating to a famous English scientist" , "of a famous mathematician" , "using non-relativistic laws" .)