Seated strangely in a demure sort of way (6)
I believe the answer is:
sedate
'seated strangely in a demure sort of way' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for sedate that I've seen before include "Calm, sober" , "Calm or spectral appartition" , "Give calming drug to" , "Calm, unhurried" , "Staid; put to sleep" .)