index

/ˈɪndɛks/Loanword from Latinindex
alphabetical list

The book's index helped me find the chapter quickly.

The index is a list that lets you locate information.


formal

A list of topics or terms with page numbers, usually at the back of a book.

You can look up the word in the index to see where it appears.

The index shows the pages where the word is mentioned.

Commonly used in printed books, reports, and manuals.

Technology
technical

A data structure that improves the speed of data retrieval operations in a database.

Creating an index on the 'email' column speeds up search queries.

The index makes searching by email faster.

Often a B‑tree or hash structure; essential for large tables.

Finance
formal

A statistical measure that reflects the relative change in a set of prices or values over time.

The consumer price index rose 0.3% last month.

The CPI, a type of index, shows a small increase.

Examples include CPI, stock index, and price index.

Collocations

index funda mutual fund that tracks a market indexstock indexa statistical measure of a set of stocksindex numbera numeric indicator used for comparison over time
English Dictionary