What is the meaning of Keyword?

Any word used as the key to a code.

Any word used in a reference work to link to other words or other information.

Any important word in a text or document, which may be linked to other words or other information, or listed in the metadata for searches to find.

A reserved word used to identify a specific command, function, etc.

Any word that occurs in a text more often than normal.

To tag with keywords, as for example to facilitate searching.

keyword

Source: wiktionary.org