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; not only do the two somewhat uncommon words look and sound alike, they also come from the same root, the Middle French word essai, meaning "test" or "effort." (Essai, in turn, comes from the Late Latin word exagium, meaning "act of weighing.") At one time, the two terms were synonyms, sharing the meaning "try" or "attempt," but they are now typically differentiated, with essay meaning "to try or attempt" (as in "a comedic actor essaying her first dramatic role") and assay meaning "to test or evaluate" (as in "blood assayed to detect the presence of the antibody"). Of course, essay is more common as a noun referring to a short analytic or personal literary composition, but that’s another essay.

Examples of assay in a Sentence

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
Then the curtains will close on Morgan’s particular view of this famously inscrutable family, assayed by so many indelible actors. Lisa Rosen, Los Angeles Times, 27 Nov. 2023 So, the authors ran a series of enzymatic assays to determine how much different red wine flavonoids inhibited ALDH2. Jennifer Ouellette, Ars Technica, 20 Nov. 2023 This is a golden opportunity to do the standard shadow primary work of defining yourself and defining your opponent, creating some clear terms by which voters can easily assay the differences between your campaign and Trump’s. Alex Shephard, The New Republic, 3 Aug. 2023 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 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 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
Noun
Highlights from the assay results from the three holes are as follows: Highlights: CVZ-087 66.3 meters at 1,153 ppm Li from 18.0 meters to 84.3 meters, including 6.8 meters at 1,783 ppm Li from 36.3 meters to 43.1 meters. Fort Worth Star-Telegram, 25 Jan. 2024 The results are mixed and, in some cases, hard to compare due to differences in intervals between vaccination, the number of people involved, and the types of assays used. Beth Mole, Ars Technica, 27 Jan. 2023 By inspecting the heated feathers under a microscope and using a chemical assay to identify different types of melanin, the team found that biological pigments do leave a distinct and identifiable signature in fossils. Riley Black, Scientific American, 14 Dec. 2023 In preliminary assays of vulture fluids and tissue samples, researchers have identified beneficial microbes that block Yersinia pestis, the bearer of plague, and listeria, the cause of food poisoning. Natalie Angier, New York Times, 12 Nov. 2023 Although life-science reagents suppliers like NEB sell research-grade isothermal amplification kits for less than US $2 per test, the sticker price for consumer assays range from $50 to $75 a pop (with an additional one-time hardware cost of between $25 and $250 for some commercial products). IEEE Spectrum, 24 Jan. 2022 That testing includes a seven-drug assay similar to the urine tests used by many probation departments, as well as a separate test for fentanyl. Kate Linthicum, Keri Blakinger and Connor Sheets, Anchorage Daily News, 15 July 2023 Last year, the European Medicines Agency gave its blessing to a commercial assay that offers a simple way for scientists and public health officials to measure T-cell immunity. Melissa Healy, Los Angeles Times, 20 Mar. 2023 This is a new concept, with the goal of enabling testing facilities distributed globally to produce a standardized diagnostic assay in response to an emerging biothreat the moment the assay is validated. Sylvain Gariel, Forbes, 15 Aug. 2022

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'assay.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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 19 Mar. 2024.

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

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