What is the meaning of Born-again?

Having been spiritually changed through faith.

Having a renewed commitment to Jesus Christ.

Of or pertaining to evangelicalism.

Having a newly won zeal for some activity.

Utter; out-and-out.

Someone who has been spiritually changed through their (Christian) faith.

Someone who has a renewed commitment to Jesus Christ.

An evangelical Christian.

Anyone with a renewed commitment to any kind of cause or belief.

Source: wiktionary.org