thumb index
Appearance
English
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Blacks-Law-Dictionary.jpg/220px-Blacks-Law-Dictionary.jpg)
Noun
[edit]thumb index (plural thumb indexes)
- A series of alphabetically marked or otherwise labelled semicircular cut-outs in the fore edge of a large reference book, encyclopaedia, Bible, etc., that allows quick access to various parts of the text.
- Coordinate term: edge index