Concentration /(?)/

Con·cen·tra·tion

Concentration

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.
    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. (Metal.)