subindex
nounUK /ˈsʌbˌɪndeks/
US /ˈsʌbˌɪndeks/
A smaller list inside a big list that helps you find things.
The book's subindex lists all the animals mentioned in the chapter.
OTHER MEANINGS
2. A number that shows a smaller part of a larger measurement.
The subindex for food prices rose faster than the main index.
3. A secondary or lower-level index in a database or filing system.
Each record has a subindex that speeds up searching by date.
4. In mathematics, a subscript or lower index used to label a term.
The subindex i marks each term in the sequence.