The symbol for zero, or 0, is from the Hindu numeral which looked just like it, which obviously conveys emptiness because of the perceived hole we see. The concept of zero also originated in India, as did the word for it. Etymologists know for sure we got it from Italian zero, since the Italians were first in contact with the Arabs who used the word sifr, which meant "zero" and is the etymon of the word cipher (which, for those of you who don't know, today means "code" but previously also meant "zero"), through Italian cifra and French cifre. Sifr, which also took on the meaning of "void" as it continued in Arabic, can be followed back to the earlier Arabic word safara, which meant "the quality of being empty" (curiously, the same character for this also represents the second month in the Muslim calendar). This in turn has origins in the Sanskrit word sunyas, defined along the lines of "empty".
Hello! I'm Adam Aleksic, a sophomore studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy politics, vexillology, geography, board games, conlanging, and law.