Thayer's Greek Lexicon

 1. a state of national tranquillity
  1) exemption from the rage and havoc of war
2. peace between individuals, i.e. harmony, concord
3. security, safety, prosperity, felicity, (because peace and
harmony make and keep things safe and prosperous)
4. of the Messiah's peace
  1) the way that leads to peace (salvation)
5. of Christianity, the tranquil state of a soul assured of its
salvation through Christ, and so fearing nothing from God and
content with its earthly lot, of whatsoever sort that is
6. the blessed state of devout and upright men after death