Webster's Revised Unabridged Dictionary · 1913

Assay

Assay ({not transcribed}) , noun

[Old French asai, essai, trial, French essa. See Essay, n.]

1.
Trial; attempt; essay. [Obsolete] — Chaucer
I am withal persuaded that it may prove much more easy in the assay than it now seems at distance. — Milton
2.
Examination and determination; test; as, an assay of bread or wine. [Obsolete]
This can not be, by no assay of reason. — Shakespeare
3.
Trial by danger or by affliction; adventure; risk; hardship; state of being tried. [Obsolete]
Through many hard assays which did betide. — Spenser
4.
Tested purity or value. [Obsolete]
With gold and pearl of rich assay. — Spenser
5.
(Metallurgy) The act or process of ascertaining the proportion of a particular metal in an ore or alloy; especially, the determination of the proportion of gold or silver in bullion or coin.
6.
The alloy or metal to be assayed. — Ure

Assay is used adjectively or as the first part of a compound; as, assay balance, assay furnace.

Collocations (2)
Assay master , an officer who assays or tests gold or silver coin or bullion.
Assay ton , a weight of 29,166⅔ grams.

Assay ({not transcribed}) , transitive verb

[Old French asaier, essaier, French essayer, from essai. See Assay, n., Essay, v.]

1.
To try; to attempt; to apply. [Obsolete or Archaic]
To-night let us assay our plot. — Shakespeare
Soft words to his fierce passion she assayed. — Milton
2.
To affect. [Obsolete]
When the heart is ill assayed. — Spenser
3.
To try tasting, as food or drink. [Obsolete]
4.
To subject, as an ore, alloy, or other metallic compound, to chemical or metallurgical examination, in order to determine the amount of a particular metal contained in it, or to ascertain its composition.

Assay , intransitive verb

To attempt, try, or endeavor. [Archaic In this sense essay is now commonly used.]
She thrice assayed to speak. — Dryden