cedilla (n.)youdaoicibaDictYouDict[cedilla 词源字典]
c. 1600, from Spanish cedilla, zedilla, literally "little z," from a Latin-like diminutive of Greek zeta "the letter 'z'." The mark (formerly also used in Spanish) was derived from that letter and indicates a "soft" sound in letters in positions where normally they have a "hard" sound. See zed.[cedilla etymology, cedilla origin, 英语词源]