demure
adj.adj. behaving in a quiet and polite way that doesn't attract attention. It's often used to describe someone who seems shy and well-behaved.
adj. quiet, reserved, and modest in behaviour or appearance. Typically used to describe women, it can connote shyness or a conventional sense of propriety.
She gives a demure smile and looks away.
Contrary to her on-screen persona, the actress was quiet and demure in person, avoiding the press.
The character's demure exterior concealed a sharp wit and a fiercely independent spirit, subverting the expectations set by her quiet demeanor.
Inherited from Middle English demure, demwre, an abbreviation of Anglo-Norman de mure port (“with a mature demeanor”) (compare Old French meur from Latin mātūrus): *si il seyt coy e de mure port (Amur curteiz) (“he sits quietly and with a mature appearance”) * Documents illustrating the history of Scotland, CLV, 1306, Orders for the custody of Scottish prisoners, CLV: …et que eles soient de bon et meur port (“…with a good and mature demeanor”) * mss. Arundel, 220: ke cely qe vus amerez soyt de gentil manere, coy, de meure porture (“with a mature demeanor”) * (Monastic rule): de aunciene dame de meure porture ke pusse les plus ieuenes rieueler e endoctriner (“an old lady with a mature demeanor able to rule and educate the young girls”).