Definitions
1.NounText or any data that is to be encrypted (as opposed to ciphertext)."Using the sophisticated code was useless since the spy merely stole the plain text from the waste basket."
2.NounHuman readable text which consists only of a string of characters, represented using a character encoding such as ASCII or Unicode. In the file format sense, plain text may represent structured data in a human readable format such as XML.
3.NounData which consists only of human-readable unformatted text, as opposed to machine-readable binary data or formatted/structured text. In this sense, the character data in between XML tags may be called "plain text".
4.AdjectiveAlternative spelling of plaintext.