thumb index

¹

noun

1. a series of labeled notches cut along the fore edge of a book, to indicate the divisions or sections.

thumb-index

²

[ thuhm-in-deks ]

verb (used with object)

1. to provide (a book) with a thumb index.

thumb index

noun

1. a series of indentations cut into the fore edge of a book to facilitate quick reference

verb

1. tr to furnish with a thumb index

Word History and Origins

Origin of thumb index¹

First recorded in 1900–05

Example Sentences

Steel strings twang with each pull from the metal rings — wearable guitar picks — adorning his right thumb, index and middle finger.

From Los Angeles Times

Afterward, he held out his thumb, index and little fingers, signing a message to his community and beyond: “I love you.”

From Los Angeles Times

“An umpire checking a pitcher for foreign substances will use his thumb to check for stickiness on the pitcher’s thumb, index finger, middle finger, and palm,” Hill wrote.

From Seattle Times

The controllers also have haptic feedback, and finger touch detection that will let them detect fingers without having to press areas where you rest your thumb, index, or middle fingers.

From The Verge

Both have the same tattoo - a hand with thumb, index finger and pinkie finger up and the ring finger and middle finger down.

From Washington Times