Lingerie items donned by royal composer (6)
I believe the answer is:
brahms
'composer' is the definition.
(I know that Brahms is a composer)
'lingerie items donned by royal' is the wordplay.
'lingerie items' becomes 'bras' (I've seen this in another clue).
'donned by' is an insertion indicator.
'royal' becomes 'hm' (His or Her Majesty).
'bras' going around 'hm' is 'BRAHMS'.
(Other definitions for brahms that I've seen before include "drunk?" , "Composer of a well-known lullaby published in 1868" , "German scorer" , "Half-drunk composer" , "German Romantic composer" .)