symbol (n.)

mid-15c., simbal, "creed, formal summary of religious belief," from Late Latin symbolum "creed, token, mark," from Greek symbolon "token, watchword, sign by which one infers; ticket, a permit, license," etymologically "that which is thrown or cast together." It is from assimilated form of syn- "together" (see syn-) + bole "a throwing, a casting, the stroke of a missile, bolt, beam," from bol-, nominative stem of ballein "to throw" (from PIE root *gwele- "to throw, reach").

The sense evolution in Greek is from "throwing things together" to "contrasting" to "comparing" to "token used in comparisons to determine if something is genuine." The Greek word was applied c. 250 by Cyprian of Carthage to the Apostles' Creed, on the notion of the "mark" or "outward sign" that distinguishes Christians from pagans.

Hence also "something which stands for something else," especially "object standing for or representing something sacred, moral, or intellectual" (1580s); "a written character, mark, or sign which stands for something" (1610s).