With special sense, muse about new language (9)
I believe the answer is:
esperanto
'language' is the definition.
(Esperanto is an example)
'with special sense muse about new' is the wordplay.
'with special sense' becomes 'esp' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'muse' becomes 'erato' (Erato is an example).
'about' is an insertion indicator.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'erato' going around 'n' is 'eranto'.
'esp'+'eranto'='ESPERANTO'
Can you help me to learn more?
(Other definitions for esperanto that I've seen before include "Linguistic invention" , "Language invented by Dr Zamenhof" , "special speech" , "Ape tenors (anag.)" , "Artificial international language devised in 1887" .)