1.
If you describe someone, usually a young woman, as ~, you mean they are quiet and rather shy, usually in a way that you like and find appealing, and behave very correctly.
She’s very ~ and sweet...
ADJ approval
~ly
She smiled ~ly.
ADV: usu ADV with v
2.
Demure clothes do not reveal your body and they give the impression that you are shy and behave correctly. (WRITTEN)
...a ~ high-necked white blouse.
ADJ: usu ADJ n
~ly
She was ~ly dressed in a black woollen suit.
ADV: ADV -ed, ADV after v