Keyword (noun)

1. A word or phrase used as a filter to retrieve information from a database or the Internet based on a specific search query.
2. A significant or central word in a text, document, or speech.

Origin:

Mid 19th century: from key, in the sense "something that serves to unlock or explain", + word.

Examples:

1. She entered several keywords into the search engine to find relevant information.
2. The keywords used in the article were 'artificial intelligence' and 'machine learning'.
3. The keyword was highlighted in bold in the document.
4. The marketing team selected keywords to optimize their website for search engines.
5. The keyword 'climate change' was mentioned several times in the speech.