assay

American  

[a-sey, as-ey, a-sey] / æˈseɪ, ˈæs eɪ, æˈseɪ /

verb (used with object)

• assays,
  present (3rd person singular)
• assayed,
  past participle,  past
• assaying
  present participle

1. to examine or analyze.

   to assay a situation; to assay an event.

2. Metallurgy. to analyze (an ore, alloy, etc.) in order to determine the quantity of gold, silver, or other metal in it.

3. Pharmacology. to subject (a drug) to an analysis for the determination of its potency or composition.

4. to judge the quality of; assess; evaluate.

   to assay someone's efforts.

5. to try or test; put to trial.

   to assay one's strength; to assay one's debating abilities.

6. to attempt; try; essay.

   to assay a dance step.

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verb (used without object)

• assays,
  present (3rd person singular)
• assayed,
  past participle,  past
• assaying
  present participle

1. to contain, as shown by analysis, a certain proportion of usually precious metal.

noun

• assays
  plural

1. Metallurgy. determination of the amount of metal, especially gold or silver, in an ore, alloy, etc.

2. a substance undergoing analysis or trial.

3. a detailed report of the findings in assaying a substance.

4. Archaic. examination; trial; attempt; essay.

assay British  

verb

1. to subject (a substance, such as silver or gold) to chemical analysis, as in the determination of the amount of impurity

2. (tr) to attempt (something or to do something)

3. (tr; may take a clause as object) to test, analyse, or evaluate

   to assay the significance of early childhood experience

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noun

1. 1. an analysis, esp a determination of the amount of metal in an ore or the amounts of impurities in a precious metal

   2. ( as modifier )

      an assay office

2. a substance undergoing an analysis

3. a written report on the results of an analysis

4. a test

5. archaic an attempt

assay Scientific  

/ ăs′ā,ə-sā′ /

1. A quantitative determination of the amount of a given substance in a particular sample. Assays are regularly used to determine the purity of precious metals. They can be performed by wet methods or dry methods. In the wet method, the sample is dissolved in a reagent, like an acid, until the purified metal is separated out. In the dry method, the sample is mixed with a flux (a substance such as borax or silica that helps lower the melting temperature) and then the sample is heated to the point where impurities in the metal fuse with the flux, leaving the purified metal as a residue.

2. A bioassay.

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Other Word Forms

Derived Forms

• assayer
  noun
• assayable
  adjective
• unassayed
  adjective
• unassaying
  adjective

Inflected Forms

Nouns

• assays
  plural

Participles

• assaying
  present
• assayed
  past

Conjugated Forms

Present

• assay
  simple
• assays
  simple
• have assayed
  perfect
• has assayed
  perfect
• am assaying
  progressive
• are assaying
  progressive
• is assaying
  progressive
• have been assaying
  perfect progressive
• has been assaying
  perfect progressive

Past

• assayed
  simple
• had assayed
  perfect
• was assaying
  progressive
• were assaying
  progressive
• had been assaying
  perfect progressive

Future

• will assay
  simple
• will have assayed
  perfect
• will be assaying
  progressive
• will have been assaying
  perfect progressive

Etymology

Origin of assay

1250–1300; Middle English < Middle French; variant of essay

Explanation

An assay is a breakdown of a material, examining the individual parts that make up the whole. When you assay a situation, you look at all the elements that created the problem in order to come up with a solution. The word assay comes from the French word essai, which means "trial," an appropriate sense for a word that means to examine for analysis. As a noun, assay means a test or appraisal to determine the components of a substance or object. As a verb, it refers to the act of analyzing, or of conducting that test. It is usually used in chemistry-related fields like metallurgy and pharmaceuticals, but you can also assay a poem.

Example Sentences

See Examples For:

assay assays assayed assaying

Dash, whose team includes former software engineers from Moderna, automates common laboratory tests such as Elisa, or enzyme-linked immunosorbent assay, which is used for tasks such as evaluating a drug’s safety and efficacy.

From The Wall Street Journal ● Jul. 23, 2025

We set up an inhibition assay in test tubes.

From Salon ● Dec. 16, 2024

The new assay aligns with ongoing efforts by state and federal agencies, which have invested more than $10 million from 2004 to 2021 to manage the Burmese pythons alone.

From Science Daily ● Nov. 22, 2024

In contrast, the newly developed tetraplex assay by UF/IFAS scientists can identify DNA traces of these snakes even weeks after they have left an area.

From Science Daily ● Nov. 22, 2024

By the mast pond, where the great spars of ships lay refracted, we saw a little girl with a bucket, a vain and minute assay at extinguishing the flames.

From "The Astonishing Life of Octavian Nothing, Traitor to the Nation, Volume II: The Kingdom on the Waves" by M.T. Anderson

Mr. Currey asks an important question about Genet, but assays no answer: “Was it prison that enabled his writing, or was it the act of theft that he practiced so assiduously during all those years?”

From The Wall Street Journal ● Apr. 10, 2026

Typically Elisa assays are built from scratch for a specific application.

From The Wall Street Journal ● Jul. 23, 2025

"Our computational approaches further allowed us to identify and analyze these rare events that are not visible with standard sequencing assays."

From Science Daily ● Nov. 20, 2024

As health officials turn increasingly toward wastewater testing as a means of tracking the spread of H5N1 bird flu among U.S. dairy herds, some researchers are raising questions about the effectiveness of the sewage assays.

From Los Angeles Times ● May 16, 2024

If such a haplogroup turned up in Pena’s assays, it could write a new chapter in the early history of Native Americans.

From "1491" by Charles C. Mann

Then the curtains will close on Morgan’s particular view of this famously inscrutable family, assayed by so many indelible actors.

From Los Angeles Times ● Nov. 27, 2023

On the other hand, transformation is often assayed by incorporating an antibiotic-resistance gene in the plasmid to be transferred into the host organism.

From Textbooks ● Jun. 9, 2022

It put him at the head of a trio that assayed the compositions of Steve Swallow, a bassist/composer and Scofield’s mentor.

From Washington Post ● Aug. 27, 2021

By using the best of four reaction conditions, 187 additional products were produced and assayed that bound to CHK1; the colour of the dots reflects the affinity ranking of the compounds.

From Nature ● Apr. 22, 2018

A sloop’s crew assayed flight in their longboat, but they were overtaken.

From "The Astonishing Life of Octavian Nothing, Traitor to the Nation, Volume II: The Kingdom on the Waves" by M.T. Anderson

"The refined bullion is analysed to the highest levels of accuracy, on various methods of gold assaying," says James Jose, managing director at CGR.

From BBC ● Mar. 28, 2024

When Sterling-Duprey reappears onstage with her headlamp, she might be assaying the damage.

From New York Times ● Mar. 5, 2023

But assaying information — weighing it, analyzing it, separating the gold from the pyrite — still depends on old-fashioned human judgment.

From Washington Post ● Dec. 24, 2021

Word reaches us that Mr. Ben Schwartz has accepted an engagement at the Paramount Studios of Hollywood, California, where he will be assaying the role of Sonic the Hedgehog.

From Slate ● Aug. 9, 2018

"But the man who proposed buying it would send an expert to collect samples for assaying."

From A Damaged Reputation by Harold Bindloss