Keyword may mean:

• Keyword (computer), an identifier in a computer language that indicates a specific command
• Keyword (linguistics), a word that occurs with unexpected frequency in a text
• Keyword (cryptography), a word which is the key to a code or cipher
• Keyword (America Online), an addressing scheme used on America Online as an alternative to URLs
• A word describing a concept found in a document such as a Web page, constituting part of the metadata for the document; for instance, see Tags, Keyword stuffing, Text retrieval
• A word or concept with special significance.

In a non-computer sense:

• A Vocabulary of Culture and Society - a 1976 book discussing English words and their cultural use

Meta tags are pieces of code within your website that contain information about each page. Deskriptor | Słowo kluczowe | Ключевое слово | คีย์เวิร์ด | 关键词