1. The word, sim’wa, originated on the extraordinary 1990s science fiction series, Babylon 5. (See the graphic at the bottom of the page.) The expression is regarded as canonical (that is to say, officially approved), since it can be heard in a televised screenplay (the episode, And Now for a Word) written by the show’s creator, J. Michael Straczynski (JMS).
   
   Literally, sim’wa is rendered from Adronato, the language of the Minbari religious caste (including the characters, Delenn and Lennier), as in peace. (Adronato is one of the three major Minbari caste-based languages. The other two are Feek and Lenn’a.) Functionally, however, sim’wa is spoken, like most of the other items in this list, as a salutation (a greeting). The expression, “Nie’se schlect sim’wa ai’ linn,” translates as, “Your friend in both peace and war.”
2. Prî lâni is peace among the Mayanga first nations people of Nicaragua and Honduras.
3. Peace be with you or peace to you is used in some branches of Christianity and in other contexts.
4. The peace fingers sign (like the sign for victory) was especially common within the peace movement of the 1960s. It was employed as both a salutation and a valediction (a goodbye).
5. A common peace sign (credit: Wikimedia).
6. Peace out, often accompanied by punching one’s chest with one’s fist, is a later variant more frequently used as a valediction than as a salutation.
7. Various cognates (related words) of the Semitic root, S-L-M, are also used as salutations:
   1. Salām is Arabic for peace. as-Salāmu ʿālaykum is peace be upon you. In Irān, salām, by itself, is more commonly heard than as-salāmu ʿālaykum.
   2. Šālōm (shalom) is Hebrew for peace. Šālōm ʿalayẖum is peace be upon you.
   3. The Semitic sliem and the Indo-European paċi are both Maltese for peace. Sliem lilek is peace to you. Maltese is the only Semitic language written in the Roman alphabet – though with the addition of some letters. Sliem għalikom is the Muslim greeting, peace to you. Paċi mingħand is peace to you.
   4. Šlama (Assyrian/Syriac/Aramaic, ܫܠܡܐ) is Aramaic (Assyrian/Syriac) for peace. Šlama ʿlok (Assyrian/Syriac/Aramaic, ܫܠܡܐ ܥܠܘܟ) is peace be upon you.
   5. Sälamə (ሰላም) is Amharic/ʾÄmarəña for peace. Sälamə läʾənanətä (ሰላም ለእናንተ) is peace to you.
   6. salāmūnā (سَلَامُونَا) is peace be upon you in Paṣ̌tū (Pashto).
8. anata ni sarāmu (Japanese/Nihongo, あなたにサラーム) is salam to you.
9. sàlāmǔgěinǐ (Chinese/Zhōngwén, 萨拉姆给你) is salam to you.
10. tōmāra sālāma (Bengali/Bāṅāli/Bānlā, তোমার সালাম) is salam to you.
11. Síochá is Irish Gaelic for peace. Síocháin duit is peace be upon you.
12. Püd is Volapük for peace. Püd binonös lü ols is peace be with you.
13. Pāx is Latin for peace. Pāx vōbīscum is peace be upon you.
14. Paco is Esperanto (a constructed language) for peace. Paco esti sur vi is peace be upon you.
15. Pags is Modern Indo-European (a constructed language) for peace. Pags esmi epi juwe is peace be upon you.
16. Paci is Glosa (a constructed language) for peace. Paci a tu is peace to you.
17. Paix is French for peace. La paix soit sur vous is peace be upon you.
18. Paix is French for peace. La paix soit sur vous is peace be upon you.
19. Paz is Spanish for peace. La paz sea en usted is peace be upon you.
20. P’yŏngwa (평화) is Korean for peace.
21. Pīsu (ピース) is Japanese for peace.
22. Pase is Novial (a constructed language) for peace.
23. Salam (from the Arabic, salām) is Lingwa de planeta (a constructed language) for peace. Salam a yu is peace to you.
24. Finally, auṃ śāntiḥ śāntiḥ śāntiḥ auṃ is a greeting in Sanskrit. While auṃ (oṃ) is regarded as the primordial sound of the universe, śāntiḥ is peace.

For additional peace greetings, see this page.