(1)   Strengthening the amount of a substance in a unit amount of another substance (as of a solute in a mixture) by removing the other substance
(2)   Bringing together military forces
(3)   Great and constant diligence and attention
(4)   (chemistry) the strength of a solution; number of molecules of a substance in a given volume (expressed as moles/cubic meter)
(5)   The spatial property of being crowded together
(6)   Complete attention; intense mental effort
(7)   Increase in density


  1. The proportion of a substance in a mixture.
    1. The amount of solute in a solution measured in parts per million (ppm)
  2. The act, process or ability of concentrating; the process of becoming concentrated, or the state of being concentrated.
    1. The act, process or product of reducing the volume of a liquid, as by evaporation.
    2. 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.
  3. A field or course of study on which one focuses, especially as a student in a college or university.