noun

• The act, process or ability of concentrating; the process of becoming concentrated, or the state of being concentrated.
• The direction of attention to a specific object.
• The act, process or product of reducing the volume of a liquid, as by evaporation.
• 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.
• A field or course of study on which one focuses, especially as a student in a college or university.
• The proportion of a substance in a whole.
• (chemistry) The amount of solute in a solution measured in suitable units (e.g., parts per million (ppm))
• The matching game pelmanism.