Root meaning before "hello"
Wiktionary traces shalom to the triliteral root שׁ־ל־ם, related to completeness and welfare, not only the absence of conflict. That is why Hebrew shalom aleichem is literally "peace be upon you," and the reply aleichem shalom reverses the same noun.
English dictionaries record shalom as a loanword for the greeting and for the peace sense in religious or diplomatic English. The word is older than its casual English use; Biblical Hebrew already uses shalom for welfare and safety.
Greeting, farewell, and fixed phrases
Shalom alone can open or close a conversation in Hebrew, though time-specific phrases (boker tov, erev tov) are also common. Shalom aleichem / aleichem shalom is the best-known paired formula; lehitraot covers "see you later" with a different construction.
Yiddish oy vey expresses dismay, not greeting. English sometimes groups Jewish-origin interjections together; shalom and oy vey belong to different languages and jobs.
English borrowings nearby on LingoGrove
Arabic peace formulas on this site include inshallah and mashallah, which carry religious "God willing" semantics unlike shalom's root sense of wholeness. Spanish loanwords such as de nada show how a literal "of nothing" becomes a fixed social reply; shalom likewise does more than a one-word gloss "peace" captures in English.