gnomon

noun gno·mon \ ˈnō-mən , -ˌmän \

Definition of gnomon

1 : an object that by the position or length of its shadow serves as an indicator especially of the hour of the day: such as

a : the pin of a sundial

b : a column or shaft erected perpendicular to the horizon

2 : the remainder of a parallelogram after the removal of a similar parallelogram containing one of its corners

See gnomon defined for kids

Recent Examples of gnomon from the Web

There are many types of sundials, but in general each consists of a gnomon, a thin rod that casts a shadow onto a dial, and a flat plate or platform.

— megan arnett, Scientific American, "It's About Time... to Make a Sundial!," 15 Mar. 2018
The original clock is missing its gnomon, the part of a sundial that casts a shadow, but an 18th-century museum curator described it having one in the shape of a pig’s tail, so Parslow re-created that, too.

— National Geographic, "Ancient Sundial Shaped Like Ham Was Roman Pocket Watch," 19 Jan. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'gnomon.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.