a mathematical element that when added to another number yields the same number
a quantity of no importance;
"it looked like nothing I had ever seen before"
"reduced to nil all the work we had done"
"we racked up a pathetic goose egg"
"it was all for naught"
"I didn't hear zilch about it"
"We should encode the message for security reasons"
make a mathematical calculation or computation
cipher的用法和样例：
例句
用作名词 (n.)
The army uses a special cipher so that military messages are kept secret. 军队使用一种特殊密码,军事电讯因此得以保密。
The cipher took me three weeks before I hit it. 我费了3个多星期才把这密码解释出来。
Age is only a number, a cipher for the records. A man can't retire his experience. He must use it. Experience achieves more with less energy and time. 年龄只是个阿拉伯数字。一个人不能让他的经验退休。他必须用它。依靠经验，可以用较少的精力和时间获得更多。
