concentration

noun

1. (uncountable, usually)The act, process or ability of concentrating; the process of becoming concentrated, or the state of being concentrated.

   “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.”

2. (uncountable, usually)The act, process or ability of concentrating; the process of becoming concentrated, or the state of being concentrated.
3. (uncountable, usually)The act, process or ability of concentrating; the process of becoming concentrated, or the state of being concentrated.
4. (uncountable, usually)The act, process or ability of concentrating; the process of becoming concentrated, or the state of being concentrated.
5. (uncountable, usually)A field or course of study on which one focuses, especially as a student in a college or university.
6. (uncountable, usually)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.”

   “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.”

7. (physical, uncountable, usually)The proportion of a substance in a whole.
8. (uncountable, usually)The matching game pelmanism.