Publicity people notice a fashion label (5)
I believe the answer is:
prada
'fashion label' is the definition.
(Italian fashion house)
'publicity people notice a' is the wordplay.
'publicity people' becomes 'PR' (public relations).
'notice' becomes 'ad' (both can mean an advertisement).
'pr'+'ad'+'a'='PRADA'
(Other definitions for prada that I've seen before include "Design house" , "Milan outfit" .)