am·​y·​loid | \ ˈa-mə-ˌlȯid How to pronounce amyloid (audio) \

Definition of amyloid

: 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

Other Words from amyloid

amyloid adjective

Examples of amyloid in a Sentence

Recent Examples on the Web The patient population is narrower than the one the FDA approved the drug to treat, as the FDA did not require proof of amyloid plaques. Rachel Cohrs, STAT, 9 Apr. 2022 Beta amyloid plaques in the brain are one of the hallmark signals of Alzheimer's, along with tangles of a protein called tau. Sandee Lamotte, CNN, 23 Mar. 2022 The agency’s justification was that Aduhelm targets a protein, amyloid, that forms plaques in the brains of Alzheimer’s patients. New York Times, 7 Apr. 2022 Clinical trials are also sometimes the only way for people to access diagnostic tools such as PET scans, which determine if amyloid plaques — a hallmark of Alzheimer’s — are present in the brain. Caroline Catherman, Orlando Sentinel, 15 Apr. 2022 Light chain amyloid is closely related to multiple myeloma and similar blood abnormalities. Dr. Keith Roach, oregonlive, 4 Feb. 2022 The amyloid deposits are associated with advanced disease. Scott Gottlieb, WSJ, 27 Jan. 2022 The requirement for clinical studies applies to the entire class of drugs of which Aduhelm is a pioneer, monoclonal antibodies directed against amyloid. Ricardo Alonso-zaldivar, USA TODAY, 12 Jan. 2022 But many Alzheimer’s specialists say that extensive research has shown little evidence that reducing amyloid slows cognitive decline. New York Times, 11 Jan. 2022 See More

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

First Known Use of amyloid

1866, in the meaning defined above

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Time Traveler for amyloid

Time Traveler

The first known use of amyloid was in 1866

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Dictionary Entries Near amyloid



amyloid beta

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Statistics for amyloid

Last Updated

12 May 2022

Cite this Entry

“Amyloid.” Dictionary, Merriam-Webster, Accessed 20 May. 2022.

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More Definitions for amyloid


am·​y·​loid | \ ˈam-ə-ˌlȯid \

Medical Definition of amyloid

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

Other Words from amyloid

amyloid adjective

More from Merriam-Webster on amyloid Encyclopedia article about amyloid


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