A falcon that is not yet accustomed to being around humans is referred to as being “unmanned.” To calm its nerves and keep it from beating its wings, a black hood is placed over it. Juliet is described as “unmanned” in the sense that she’s never spent the night with a man, and she is calling on Night to cover her nervousness with darkness and hide the beating in her cheeks — her blushing — until she grows accustomed to the act of love-making.