active mass

American  

noun

Chemistry.

1. the effective concentration of a substance.

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Etymology

Origin of active mass

First recorded in 1905–10

Example Sentences

Pita has maintained iTV was not an active mass media organisation.

From Reuters

Eventually, he adds, “all active mass movements strive . . . to interpose a fact-proof screen between the faithful and the realities of the world.”

From Washington Post

But for a time the Tea Party was the most active mass movement in American politics and its influence on the Republican Party cannot be overstated.

From Salon

The French secondary army in Switzerland was in the hands of the bold and active Mass�na.

From Project Gutenberg

At week's end active mass resistance appeared to have been suppressed.

From Time Magazine Archive