Paper dictionaries often have cut-outs in the pages that make it easier to turn to (words beginning with) each letter. Here's a picture:

Dictionary with notched edge

I know there's a name for these things but I can't remember what it is and it's remarkably hard to search for information about dictionaries — the search engines insist on bringing up dictionary definitions of the keywords you try. Anyone know the word?


Index Notches.

How to make Index Notches

And here's a patent for a device to cut index notches.

  • 9
    The book you linked to is full of gems! – Francesco Jun 16 '17 at 18:28
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    I selected this answer over the other one, even though "thumb index" is much more frequently used, because I wanted the term for an individual notch, not for the whole set. – zwol Jun 19 '17 at 15:26
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    It never occurred to me that I could do this myself with my own notebooks. (There must be a word for this mental state...) – Beta Jun 19 '17 at 15:56

Wikipedia calls this a thumb index. It is also frequently used with bibles for quickly finding each book.

EDIT: To clarify, this refers to the whole set of notches. The individual notches can be called thumb tabs (as given by Chris H in the comments), index notches (as given in Davo's answer), or thumb notches.

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    Also "thumb tabs" for the notches themselves. – Chris H Jun 16 '17 at 13:41
  • @ChrisH Wouldn't "thumb tabs" be something that sticks out? Those exist too, but ... – zwol Jun 16 '17 at 13:47
  • @zwol I know what you mean, but I confirmed my recollection (Bibles in Sunday School) with a quick google search (you have to exclude "guitar"). – Chris H Jun 16 '17 at 13:53
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    Minor quibble, but in a Bible the notches/tabs mark the start of each book, not each chapter - there are nearly 1200 chapters, that'd be a lot of notches! – talrnu Jun 16 '17 at 18:03
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    @TulainsCórdova I wanted the term for an individual notch, not the whole set. – zwol Jun 19 '17 at 15:26

For the want of a special word I would call them "tabs'. To distinguish them from the tabs on files perhaps we could name them as "index tabs".

  • Definitely NOT 'Tabs' Reason: Tabs 'stick out' and that name is used in so many different areas, each meaning something that sticks out. In Organ Technology, for instance, many modern consoles (keyboards) have 'Tab' stops - they stick out. So the cut-away indexing in a dictionary or Bible is simply that - it's cut away and reveals the letter at the beginning of a section or, Bible - it's cut away to reveal the name of one of the Books at its beginning. – Michael Gamble Feb 3 '20 at 18:27

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