/kon'seuhn tray"sheuhn/ , n.
1. the act of concentrating; the state of being concentrated.
2. exclusive attention to one object; close mental application.
3. something concentrated: a concentration of stars.
4. Mil.
a. the assembling of military or naval forces in a particular area in preparation for further operations.
b. a specified intensity and duration of artillery fire placed on a small area.
5. the focusing of a student's academic program on advanced study in a specific subject or field.
6. Chem. (in a solution) a measure of the amount of dissolved substance contained per unit of volume.
7. Also called memory . Cards. a game in which all 52 cards are spread out face down on the table and each player in turn exposes two cards at a time and replaces them face down if they do not constitute a pair, the object being to take the most pairs by remembering the location of the cards previously exposed.
[ 1625-35; CONCENTR(IC) + -ATION ]