Excerpt from Rabbi RC Klein‘s “What’s in a Word” column on Parshas Emor:
The Targumim often translate the Hebrew word zar into Aramaic as chiloni (for examples, see Onkelos to Ex. 29:33, 30:33 and Peirush Yonatan to Targum Yonatan to Gen. 42:7). On the other hand, the Hebrew nachri is Aramaicized by the Targumim as nochrae (see Targum to Deut. 17:15, II Sam. 15:19, Prov. 27:2). As an aside, the Targum to Psalms (81:10, 137:4) actually reverses this trend, rendering nachri as chiloniand zar as nochrae. Either way, the Aramaic word chiloni denotes foreignness or strangeness, just like zar and nachri do (see Yair to Deut. 25:5 and Me’at Tzari there).
The Midrash (Vayikra Rabbah §24:7) also uses the word chiloni in the same way that Scripture uses the word zar (i.e. non-Kohen). The Midrash explains that the Torah commands that all Jews must “be holy” (Lev. 19:2) because if they want to “walk with G-d,” then they must live up to His standards.To illustrate this idea, the Midrash cites the following parable: A Kohen Gadol was walking on the road when he happened upon a chiloni (in this case, a non-Kohen). The chiloni said to him: “I will walk with you,” to which the Kohen Gadol replied, “I am a Kohen so I will only travel in ritually pure paths and I do not walk through cemeteries. If you want to walk with me [and adhere to this higher standard], then good. But if not, then ultimately I will take leave of you and walk by myself.”The exegetical lesson of this parable underscores the notion that the zar/chiloni is alien to the Kohen Gadol because he fails to live up to the higher standard exemplified by the Kohen Gadol. In Modern Hebrew, the term chiloni refers to a “secular” or “irreligious” Jew, who is likewise estranged from Judaism and following the Torah’s precepts. He too fails to live up to the higher standard exemplified by the rest of the Jewish People and makes himself into a foreigner.