assay

1 of 2

verb

as·​say a-ˈsā How to pronounce assay (audio) ˈa-ˌsā How to pronounce assay (audio)
assayed; assaying; assays

transitive verb

1
a
: to analyze (something, such as an ore) for one or more specific components
assayed the gold to determine its purity
b
: to judge the worth of : estimate
assay the results of the new changes
2
: try, attempt
Again Israel assayed to reply, but could not.Herman Melville

intransitive verb

: to prove up in an assay
assayer noun

assay

2 of 2

noun

as·​say ˈa-ˌsā How to pronounce assay (audio) a-ˈsā How to pronounce assay (audio)
1
: examination and determination as to characteristics (such as weight, measure, or quality)
2
: analysis (as of an ore or drug) to determine the presence, absence, or quantity of one or more components
also : a test used in this analysis
3
: a substance to be assayed
also : the tabulated result of assaying
4
archaic : trial, attempt

Did you know?

Usage experts warn against confusing the verbs assay and essay. Some confusion shouldn't be surprising, since the two words look alike and derive from the same root, the Middle French essai, meaning "test" or "effort" (a root that, in turn, comes from the Late Latin exagium, meaning "act of weighing"). At one time, the two terms were synonyms, sharing the meaning "try" or "attempt," but many modern usage commentators recommend that you differentiate the two words, using essay when you mean "to try or attempt" (as in "he will essay a dramatic role for the first time") and assay to mean "to test or evaluate" (as in "the blood was assayed to detect the presence of the antibody").

Example Sentences

Verb They assayed the gold to determine its purity. the company assayed a sample of the rock to see if it contained gold in quantities worth mining Noun a metallurgist did an assay on the metal and determined it contained nickel the poem about a frustrated man's last assay at greatness
Recent Examples on the Web
Verb
Both sets of Naggs and Nells assay their parts splendidly. Peter Marks, Washington Post, 6 Feb. 2023 Farzi Yusufali: Under the guidance of geologists, mine owners and operators drill out long cores of rock for analysis, then assay each sample to determine the content. Frederick Daso, Forbes, 11 Aug. 2022 Politics has opened new possibilities for Streep’s portfolio, with several new real-life roles to assay. Armond White, National Review, 6 July 2022 An obscure testing lab was hired to assay the metal because using the leading firm in the field would supposedly alert the Canadian nickel cartel. Walter Shapiro, The New Republic, 24 Mar. 2022 How does the saliva test differ from a standard nasal swab assay for COVID-19? Tanya Lewis, Scientific American, 20 Aug. 2020 With spectrometers for assaying elements in the regolith, the briefcase-size rover hopes to make the most of the 14-Earth-day lunar day. Sanjay Kumar, Science | AAAS, 7 Sep. 2019 This Saturday, as a tribute to Previn’s memory at the opening weekend of Tanglewood, the Boston Symphony will assay the concerto, with Mutter as soloist. New York Times, 29 June 2019 But interoperability—from ad-blocking to switching app stores—is a means by which customers can assay real counteroffers. The Economist, 6 June 2019
Noun
The participants had to have first shown symptoms within the past week and to have tested positive in a rapid antigen assay. Simon Makin, Scientific American, 8 Feb. 2023 By using ceramic microcapsules of high assay low enriched uranium (HALEU) fuel, USNC's thermal nuclear engine could cut the trip in half even from optimistic estimates. Paul Douglas, Star Tribune, 12 Nov. 2020 By using ceramic microcapsules of high assay low enriched uranium (HALEU) fuel, USNC's thermal nuclear engine could cut the trip in half even from optimistic estimates. Caroline Delbert, Popular Mechanics, 9 Nov. 2020 This test, called a lateral flow assay, can be used in a doctor’s office, with results in minutes. Amber Dance, Discover Magazine, 5 May 2020 Immediately, your facilities and others produce exact replicas of the diagnostic assay the same day to begin testing local populations. Sylvain Gariel, Forbes, 15 Aug. 2022 Deploying tests, but not rapidly, because the current assay can’t be used until an infected person develops the characteristic pustules. Wired, 11 Aug. 2022 The rapid assay looks for two protein biomarkers — GFAP, found in glial cells, and UCH-L1, found in neurons. Akila Muthukumar, STAT, 12 Aug. 2022 In more pseudotype assay neutralization tests, COV44-62 and COV44-79 effectively neutralized Alpha, Beta, Gamma, Delta, Mu, Omicron BA.1, BA.2, and BA.4/5. William A. Haseltine, Forbes, 1 Aug. 2022 See More

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

Word History

Etymology

Noun and Verb

Middle English, from Anglo-French assai, essai — more at essay entry 1

First Known Use

Verb

14th century, in the meaning defined at transitive sense 2

Noun

14th century, in the meaning defined at sense 4

Time Traveler
The first known use of assay was in the 14th century

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Dictionary Entries Near assay

Cite this Entry

“Assay.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/assay. Accessed 28 Mar. 2023.

Kids Definition

assay

1 of 2 noun
as·​say ˈas-ˌā How to pronounce assay (audio)
a-ˈsā
: examination (as of an ore, metal, or drug) for the purpose of determining the presence, absence, or amount of one or more substances

assay

2 of 2 verb
as·​say a-ˈsā How to pronounce assay (audio)
ˈas-ˌā
1
2
: to analyze (as an ore) for one or more valuable substances
assayer noun

Medical Definition

assay

1 of 2 noun
as·​say ˈas-ˌā How to pronounce assay (audio) a-ˈsā How to pronounce assay (audio)
1
: examination and determination as to characteristics (as weight, measure, or quality)
2
: analysis (as of a drug) to determine the presence, absence, or quantity of one or more components compare bioassay
3
: a substance to be assayed
also : the tabulated result of assaying

assay

2 of 2 transitive verb
as·​say a-ˈsā How to pronounce assay (audio) ˈas-ˌā How to pronounce assay (audio)
: to analyze (an impure substance or mixture) for one or more specific components
the sample was assayed for drug content

More from Merriam-Webster on assay

Last Updated: - Updated example sentences
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