Serious-looking fellow embarrassed about perfume (8)
I believe the answer is:
pomander
'perfume' is the definition.
(perfumed ball)
'serious-looking fellow embarrassed about' is the wordplay.
'serious looking' becomes 'po' (as in po-faced).
'fellow' becomes 'man' (fellow can mean a man).
'embarrassed' becomes 'red' (someone may blush or go red when embarrassed).
'about' is a reversal indicator.
'red' reversed gives 'der'.
'po'+'man'+'der'='POMANDER'
(Other definitions for pomander that I've seen before include "protection against infection" , "Ball of perfume" , "source of perfume" , "A ball or of sweet-smelling substances" , "Scent container" .)