D defs.my
Entry 3 senses Webster, 1913

Concentration

/känˌ-sən-trāsh'-ən/ · Con·cen·tra·tion · IPA /ˌkɑn.sənˈtɹeɪ.ʃən/
01 n. The act or process of concentrating; the process of becoming concentrated, or the state of being concentrated; concentration.
  1. 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. 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. 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.)