That which points out; that which shows, indicates, manifests, or discloses.
- Something that serves to guide, point out, or otherwise facilitate reference, especially:
- An alphabetized list of names, places, and subjects treated in a printed work, giving the page or pages on which each item is mentioned.
- A thumb index.
- A table, file, or catalog.
- Computer Science A list of keywords associated with a record or document, used especially as an aid in searching for information.
- Something that reveals or indicates; a sign: "Her face . . . was a fair index to her disposition” ( Samuel Butler).
- A character (☞) used in printing to call attention to a particular paragraph or section. Also called fist, hand.
- An indicator or pointer, as on a scientific instrument.
- Mathematics A number or symbol, often written as a subscript or superscript to a mathematical expression, that indicates an operation to be performed, an ordering relation, or a use of the associated expression.
- A number derived from a formula, used to characterize a set of data.
- A number that represents the change in price or value of an aggregate of goods, services, wages, or other measurable quantity in comparison with a reference number for a previous period of time.
- Roman Catholic Church A list formerly published by Church authority, restricting or forbidding the reading of certain books.
- To furnish with an index: index a book.
- To enter in an index.
- To indicate or signal.
- To adjust through indexation.