Concentration

Part of speech: noun (n.)

1. The act or process of concentrating; the process of becoming concentrated, or the state of being concentrated; concentration. Concentration of the lunar beams. Boyle. Intense concetration of thought. Sir J. Herschel.

2. The act or process of reducing the volume of a liquid, as by evaporation. The acid acquires a higher degree of concentration. Knight.

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.