to restore life or consciousness to someone or something, to regain life or consciousness, or to bring something back from an unused or inactive state;
e.g. She was given some water to revive her after she fainted.
(verb)
to be filled with new energy or strength, or to fill someone or something with new energy or strength;
e.g. He drank an energy drink to revive himself after his workout.
(verb)
to improve the condition or position/status of something and make it popular again, the renew interest in something again;
e.g. The movie about ocean life will revive the interest in conserving the oceans.