Princess in Edwardian attire (5)
I believe the answer is:
diana
'princess' is the definition.
(I have seen 'British princess' mean 'diana' so perhaps 'princess' could also mean 'diana')
'in edwardian attire' is the wordplay.
'in' indicates the answer is hidden within the clue.
'DIANA' can be found hidden inside 'edwardian attire'.
(Other definitions for diana that I've seen before include "MONKEY" , "Roman goddess of the moon and the hunt" , "Roman goddess equating to Artemis" , "Girl" , "Roman goddess of the hunt, or tragic English princess" .)