Other forms: reagents
A reagent is a substance used to bring a reaction about. Add the reagent, a test reagent, reagent grade.
It is the thing you add to find out what is there, so a reagent is defined by its job rather than its chemistry. Reagent grade means pure enough for laboratory work, which is a defined standard and far purer than anything sold for industry.
1nounreagentA substance used to bring a reaction about.
“The chemist added a few drops of a reagent, and the liquid turned blue.”
reagent is a substance.
From re- plus agent, from Latin agere, to do or drive.
Latin
reagō
English, today
reagent
Possibly from Latin reagō. Compare with Norwegian Bokmål reagens. The sequence of act → action → agent → agency shows morphologic and semantic parallel, and apparent cognate relation, with react → reaction → reagent → reagency.
Etymology from Wiktionary, CC BY-SA