keyword Syllabification: (key·word)Pronunciation: /ˈkēˌwərd/Translate keyword | into French | into Italian | into Spanish Definition of keyword noun a word or concept of great significance:homes and jobs are the keywords in the campaign a word that acts as the key to a cipher or code. an informative word used in an information retrieval system to indicate the content of a document. a significant word mentioned in an index. keyword in other Oxford dictionaries Definition of keyword in the British & World English dictionary