The term "nervy" can have different meanings depending on the context, but some possible definitions are:
Courageous or bold, especially in a way that can be seen as impudent or audacious. Example: "She had the nervy audacity to ask for a raise on her first day at work."
Nervous or easily agitated. Example: "He was feeling nervy before the big presentation."
Marked by an abundance of nerve fibers or nerves. Example: "The nervy system includes the brain, spinal cord, and peripheral nerves."