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thumb index

noun

Definition of thumb index

: a series of usually labeled notches cut in the fore edge of a book (such as a dictionary) to facilitate reference

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Examples of thumb index in a Sentence

  1. a dictionary that has a thumb index

First Known Use of thumb index

1903

in the meaning defined above

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THUMB INDEX Defined for English Language Learners

thumb index

noun

Definition of thumb index for English Language Learners

  • : a series of small cuts in the edge of the pages in a large book that are labeled and that make it easier to open the book to a particular section

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