# assay

/ˈæsi/ (US) · /ɐsˈeɪ/ (UK)

Source: https://englishreference.com/word/assay
Updated: 2026-08-27

## Senses

### 1. chemical testing

noun · CEFR C1 · Technical

a test to find out how much of a specific metal or chemical is in a sample.

For teachers: a procedure in metallurgy or biology for measuring the presence, amount, or functional activity of a target entity.

- The laboratory performed an assay to check the purity of the gold coin.
- The environmental agency conducted a biological assay to determine the concentration of pollutants in the river water.

Usage: Often used with 'of' to specify the substance being tested.

### 2. to analyze a substance

verb · CEFR C1 · Technical

to test a metal or ore to see what it contains.

For teachers: to examine or analyze a substance, typically a metal or drug, to determine its components or quality.

- The miners sent the rocks to be assayed for silver content.
- Before the pharmaceutical company could release the new drug, they had to assay every batch for chemical consistency.

Usage: This verb is transitive and requires a direct object, usually the material being tested.

### 3. to attempt

verb · CEFR C2 · Literary · Formal

to try to do something, especially something difficult.

For teachers: to attempt or try a task or action; often implies a trial or testing of one's own abilities.

- He did not assay the steep climb until the weather improved.
- The young knight was eager to assay his strength against the seasoned champions in the tournament.

Teaching tip: In modern English, 'attempt' is much more common; 'assay' in this sense is restricted to high-register literature or historical contexts.

## Examples

- The lab performed an assay to check the purity of the gold.
- Before the new medication could be approved, the researchers had to complete a precise assay of its active ingredients.
- The mining company awaited the results of the chemical assay, which would determine whether the ore vein was rich enough to justify the cost of a full-scale extraction operation.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.