Which term would you use to describe a person exhibiting shyness?

The term that best describes a person exhibiting shyness is "demure." This word refers to someone who is reserved, modest, or shy in behavior or demeanor. It captures the essence of a person who may be hesitant to engage openly, often characterized by a modest or understated approach to social situations.

In contrast, "rigorous" pertains to strictness or thoroughness, which does not relate to shyness. "Provisional" refers to something temporary or subject to change, rather than a personality trait. "Inert" indicates a lack of movement or action, which is unrelated to the nuances of shyness. Thus, "demure" is the most fitting choice, focusing specifically on the characteristics associated with someone who is shy.