Main Entry: con·cen·tra·tion

Pronunciation: \ˌkän(t)-sən-ˈtrā-shən, -ˌsen-\

Function: noun

1 : the act or action of concentrating: as a : a directing of the attention or of the mental faculties toward a single object b : an increasing of strength (as of a solute or a gas in a mixture) or a purifying by partial or total removal of diluents, solvents, admixed gases, extraneous material, or waste (as by evaporation or diffusion)
2 : a crude active principle of a vegetable especially for pharmaceutical use in the form of a powder or resin
3 : the relative content of a component (as dissolved or dispersed material) of a solution, mixture, or dispersion that may be expressed in percentage by weight or by volume, in parts per million, or in grams per liter