To reanimate is to bring someone (or something) back to life, or to give them renewed energy. A new lead singer might be just the thing your band needs to reanimate its concerts.
You can reanimate someone in a literal way by giving them CPR after a heart attack — and you can also reanimate them more figuratively, simply by getting them excited about a fun weekend plan. Even if your friend is half asleep on a Monday morning in math class, the idea of a Saturday at the amusement park might be enough to reanimate her. The Latin root animare means "give breath to" and "endow with spirit."