Oxford, Noun. (plural dictionaries). Dictionary is (1) A book or electronic resource that lists the words of a language (typically in alphabetical order) and gives their meaning, or gives the equivalent words in a different language, often alsoproviding information about pronunciation, origin, and usage:I’ll look up ‘love’ in the dictionary the website gives access to an online dictionary [AS MODIFIER]: the dictionary definition of ‘smile’. (1.1) A reference book on a particular subject, the items of which are typically arranged in alphabetical order:a dictionary of quotations. (1.2) Computing A set of words or other text strings made for use in applications such asspellcheckers:the worm attempts to crack account passwords using a built-in dictionary. Glossary : Oxford, Noun. (plural glossaries). An alphabetical list of words relating to a specific subject, text, or dialect, with explanations; abrief dictionary:a glossary of Inuktitut words