Definition of assays:
(n) :
The qualitative or quantitative chemical analysis of something.
(n) :
Examination and determination; test.
(n) :
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.
(v) :
(transitive) To analyze or estimate the composition or value of (a metal, ore etc.).
(n) :
Trial, attempt.
(n) :
Tested purity or value.