cypher

nouns

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"
a person of no influence
a secret method of writing
a message written in a secret code

verbs

convert ordinary language into code
"We should encode the message for security reasons"
make a mathematical calculation or computation