concentration

Etymology

concentrate + -ion

noun

1. The act, process or ability of concentrating; the process of becoming concentrated, or the state of being concentrated.
   1. The direction of attention to a specific object.
   2. The act, process or product of reducing the volume of a liquid, as by evaporation.
   3. The act or process of removing the dress of ore and of reducing the valuable part to smaller compass, as by currents of air or water.
2. A field or course of study on which one focuses, especially as a student in a college or university.
3. The proportion of a substance in a whole.
   The Koreans Almost all the Koreans in China live in the north-eastern provinces. The greatest concentration is found in an area of approximately 1,200 square miles in Kirin Province, an area which is part of the Yen-pien Korean Autonomous Chou. 1972, Leo A. Orleans, Every Fifth Child: The Population of China, Stanford, CA: Stanford University Press, →LCCN, →OCLC, →OL, page 117
   Surprisingly, this analysis revealed that acute exposure to solvent vapors at concentrations below those associated with long-term effects appears to increase the risk of a fatal automobile accident. Furthermore, this increase in risk is comparable to the risk of death from leukemia after long-term exposure to benzene, another solvent, which has the well-known property of causing this type of cancer. 2013 July-August, Philip J. Bushnell, “Solvents, Ethanol, Car Crashes & Tolerance”, in American Scientist
   1. (chemistry) The amount of solute in a solution measured in suitable units (e.g., parts per million (ppm))
4. The matching game pelmanism.