Definition of thumb index in English:

thumb index

noun

  • A set of lettered grooves cut down the side of a book, especially a diary, address book, or dictionary, for easy reference.

    • ‘The Indexed Edition features 21 thumb indexes and comes in a gold-embossed, two-piece blue box.’
    • ‘Kent's volume is a good size for students starting out in homeopathy and has a thumb index for added ease of use.’
    • ‘These known stepped or thumb indexes are easily damaged by being folded or worn-out according to long time use and this spoils the beauty of the pocketbook and the atlas.’
    • ‘One of the key design elements of the brochure is the series of thumb indexes along the face of the book.’
    • ‘Color-coded main topic sections serve as thumb indexes and are coordinated to match the table of contents, making the sections very quick and easy to find.’

Pronunciation

thumb index