Keyword

Part of speech: noun

Definitions

1. An important term used to find or classify information in a text or database ; a reserved word with a fixed meaning in a programming language
2. A significant word chosen to index or search material in a document or database ; a protected term in programming syntax that cannot serve as a variable name
3. A meaningful term used to retrieve information from a collection ; a reserved identifier in code that carries a predefined role in the language

Etymology: The word "keyword" is a plain compound: "key" joined to "word." In its original sense, a key word was the word that unlocked the meaning of a passage, a term a reader had to grasp before the rest made sense. That figurative use of "key" as something that opens or explains something else is much older than the compound itself. The modern sense, a term used to find or index material, grew out of that idea. A keyword is the word that unlocks a document or a body of information, which is why it became the natural label for search terms in databases and later in web searching. Today's "keyword" for a search engine is, in essence, the same key that opens a passage, applied to a much larger library.

Synonyms: catchword, tag, buzzword