"government formed by election by ballot," by 1966, from Greek psēphizein "to vote" (properly "to vote with pebbles"), from psēphos "pebble, small stone," especially as used for counting and calculating (a word of uncertain origin, perhaps related to psammos "sand"), + -cracy "rule or government by."
The common method of voting in Greek cities was by dropping pebbles in different marked urns, and thus the word for "pebble" figures largely in the ancient Greek vocabulary of democracy (e.g. isopsēphos "having an equal vote"). Also a psēphados was "a juggler." Related: Psephocrat; psephocratic.