She's less than mannerly (4)
I believe the answer is:
anne
'she's' is the definition.
(I've seen this before)
'less than mannerly' is the wordplay.
'less' says the answer is hidden in the clue (the clue less some of the letters in it).
'ANNE' is hidden within 'than mannerly'.
(Other definitions for anne that I've seen before include "One of two Henry VIII wives" , "- - of Cleves" , "Stuart queen" , "Queen seventeen hundred and two to seventeen fourteen" , "23's sister" .)