From Longman Dictionary of Contemporary EnglishXMLXML /ˌeks em ˈel/ noun [uncountable] technical (extensible markup language) a way of writing a document on a computer so that its structure is clear, and so that it can easily be read on a different computer systemFrom Longman Business DictionaryXMLXML noun [uncountable]COMPUTING (eXtensible Markup Language) a computer language for creating documents that are shared on the Internet. XML makes it possible to create your own particular set of codes, allowing a document to contain large amounts of different kinds of information → compare HTML
