n. & v. (also cypher)
n. 1 a a secret or disguised way of writing. b a thing written in this way. c the key to it. 2 the arithmetical symbol (0) denoting no amount but used to occupy a vacant place in decimal etc. numeration (as in 12.05). 3 a person or thing of no importance. 4 the interlaced initials of a person or company etc.; a monogram. 5 any Arabic numeral. 6 continuous sounding of an organ-pipe, caused by a mechanical defect.
v. 1 tr. put into secret writing, encipher. 2 a tr. (usu. foll. by out) work out by arithmetic, calculate. b intr. archaic do arithmetic.
[ ME, f. OF cif(f)re, ult. f. Arab sifr ZERO ]