Maybe Rosemary's wrapped in feather boa (4)
I believe the answer is:
herb
'maybe rosemary's' is the definition.
(I know that Rosmarinus officinalis is a type of herb)
'wrapped in feather boa' is the wordplay.
'wrapped in' indicates the answer is hidden within the clue.
'HERB' is hidden in the letters of 'feather boa'.
(Other definitions for herb that I've seen before include "Plant used for flavour" , "'Sage or rosemary, say (4)'" , "Plant used in medicine or for flavouring" , "Mint possibly" , "like Basil" .)