Whenever you're filled with anxiety, you act nervously. If your friends drag you to a haunted house, you might walk nervously from one spooky room to another, eager to get out of there as soon as possible.
If you're apprehensive or uneasy, you're bound to react nervously. The shy new kid in school might smile nervously at the class, too timid to speak. A tightly-wound small dog may spend most of its anxious life trembling nervously. And although you're typically brave and brash, an attack of stage fright can leave you sweating nervously as you await your cue to begin your monologue.