köken: 진(眞) (jin, “truth”) + -짜 (-jja) of unclear origin, perhaps nativisation of 자(字) (ja, “character”, Sino-Korean) or a compound -ㅅ- (-s-) + 자(字) (ja). Presumably replaced Middle Korean 진딧 (cintis), from the same Chinese etymon and with the same meaning.