reagent

noun

re·​agent rē-ˈā-jənt 

: a substance used (as in detecting or measuring a component, in preparing a product, or in developing photographs) because of its chemical or biological activity

Examples of reagent in a Sentence

Recent Examples on the Web

So, get out the test tubes and reagents? —David Szondy august 27, New Atlas, 27 Aug. 2025

Stegra’s process uses renewable power to generate hydrogen, which is then used not as a fuel but as a chemical reagent. —Andrew Saunders, Fortune, 5 Aug. 2025

As more minerals get refined closer to home, their reagents will become indispensable. —Olumuyiwa Olowogboyega, semafor.com, 14 July 2025

Additionally, two laboratory machines were inoperable for four days in February due to a lack of reagents, which are substances used to carry out tests, because the hospital had not paid the supplier. —Scott Schwebke, Oc Register, 12 July 2025

Word History

Etymology

New Latin reagent-, reagens, present participle of reagere to react — more at react

First Known Use

1797, in the meaning defined above

Phrases Containing reagent

• Schiff reagent
• Schiff's reagent

Rhymes for reagent

• newsagent
• subagent
• agent

Medical Definition

reagent

noun

re·​agent rē-ˈā-jənt 

1

: a substance used (as in detecting or measuring a component, in preparing a product, or in developing photographs) because of its chemical or biological activity

2

: reactor sense 1b