Armorial bearings hardly unusual around the Queen (8)
I believe the answer is:
heraldry
'armorial bearings' is the definition.
(I've seen this before)
'hardly unusual around the queen' is the wordplay.
'unusual' is an anagram indicator.
'around' is an insertion indicator.
'the queen' becomes 'er' (Elizabeth Regina).
'hardly' is an anagram of 'haldry'.
'haldry' enclosing 'er' is 'HERALDRY'.
(Other definitions for heraldry that I've seen before include "System of coats of arms and the like" , "Study of coats of arms etc" , "The study of coats of arms and their owners" , "The study of crests and genealogies" , "Armorial studies" .)