: a waxy translucent substance consisting primarily of protein that is deposited in some animal organs and tissues under abnormal conditions (such as Alzheimer's disease) compare beta-amyloid
amyloid adjective

Examples of amyloid in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Richard pointed out that another amyloid-targeting antibody, solanezumab, had already been tested in cognitively normal, amyloid-positive people. — Manvir Singh, New Yorker, 2 Nov. 2026 See All Example Sentences for amyloid

Word History

First Known Use

1866, in the meaning defined above

Time Traveler
The first known use of amyloid was in 1866

Browse Nearby Words

Cite this Entry

“Amyloid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/amyloid. Accessed 9 Nov. 2026.

Medical Definition

amyloid

noun
am·​y·​loid
ˈam-ə-ˌlȯid
1
: a nonnitrogenous starchy food
2
: a waxy translucent substance consisting primarily of protein that is deposited in some animal organs and tissue under abnormal conditions (as in Alzheimer's disease) see beta-amyloid
amyloid adjective

More from Merriam-Webster on amyloid

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster