Loveliness in Mirabeau type (6)
I believe the answer is:
beauty
'loveliness' is the definition.
(thesaurus)
'in mirabeau type' is the wordplay.
'in' indicates the answer is hidden within the clue.
'BEAUTY' is hidden within 'mirabeau type'.
(Other definitions for beauty that I've seen before include "Opposite fairy tale characters" , "Supremely pleasing quality" , "- Salon; - spot" , "` `. . . . . . is only skin-deep' '" , "See 12" .)