A demure person can be described as polite and a little shy. A demure outfit is a modest one––think high neckline and low hem.

Demure is a word you don't hear a lot these days, but it used to be a huge compliment for a woman or a girl, for them to be considered shy and quiet and modest. Those days are over, thank goodness, because demure people are nice and all, but they're also a little boring.

Definitions of demure

adj affectedly modest or shy especially in a playful or provocative way

coy, overmodest
not offensive to sexual mores in conduct or appearance