gno·mon (nōmŏn′, -mən)
1. An object, such as the style of a sundial, that projects a shadow used as an indicator.
2. The geometric figure that remains after a parallelogram has been removed from a similar but larger parallelogram with which it shares a corner.
[Latingnōmōn, fromGreek, interpreter, pointer of a sundial, fromgignōskein, to know; see gnō- in the Appendix of Indo-European roots.]
(click for a larger image)
(click for a larger image)gnomon
top: on a sundial
bottom: A gnomon of the parallelogram ABCD is the shaded figure HBCDKL.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2017 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.
American Heritage Dictionary Products
The American Heritage Dictionary, 5th Edition
The American Heritage Dictionary of Idioms
The American Heritage Roget's Thesaurus
Curious George's Dictionary
The American Heritage Children's Dictionary
The American Heritage Dictionary of Indo-European Roots
The American Heritage Student Grammar Dictionary
The American Heritage Desk Dictionary + Thesaurus
The American Heritage Science Dictionary
The American Heritage Dictionary of Business Terms
The American Heritage Student Dictionary
The American Heritage Essential Student Thesaurus