Step 1: Definition of "Demure"."Demure" describes a reserved, modest, and shy person (typically a woman), often with quiet and polite behavior.
Step 2: Option Evaluation.
Withdrawn: Relates, but implies sadness or antisocial behavior, unlike "demure."
Shy: Nervous or timid around others. This is a key part of "demure."
Brazen: Bold and shameless. This is an antonym.
Brash: Rudely self-assertive. This is also an antonym.
Step 3: Closest Synonym."Shy" is the best synonym for "demure."