Definition of thumb notch
1
: a notch of a size to admit the tip of a thumb cut in the outer edges of the pages of a book for the insertion of index letters or headings — compare thumb index
2
: a half-moon cut in the sides of a slipcase to facilitate removal of the book
— called also thumb cut
Test Your Vocabulary
Name That Color
-
- Name that color:

Test your vocabulary with our 10-question quiz!
TAKE THE QUIZ
A daily challenge for crossword fanatics.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridged
Share thumb notch