a mathematical element that when added to another number yields the same number
source: WordNet 3.0
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.
source: WordNet 3.0
a person of no influence
source: WordNet 3.0
a secret method of writing
source: WordNet 3.0
a message written in a secret code
source: WordNet 3.0
See Cipher.
source: Webster 1913
verb
convert ordinary language into code
We should encode the message for security reasons.