Meaning

noun a message written in a secret code

noun a mathematical element that when added to another number yields the same number

noun a quantity of no importance

origin14th century. From Middle English cifre, from Old French cyfre, cyffre (French chiffre), ultimately from Arabic صِفْر (ṣifr, “zero, empty”), from صَفَرَ (ṣafara, “to be empty”). Doublet of chiffre and zero. Sense 8 (a fault in an organ valve) may be a different word.

Etymology from Wiktionary, CC BY-SA 3.0