v. i. To approach or meet in a common center; to consolidate; as, population tends to concentrate in cities. [ 1913 Webster ]

v. t. [ imp. & p. p. Concentrated; p. pr. & vb. n. Concentrating. ] [ Pref. con- + L. centrum center. Cf. Concenter. ] 1. To bring to, or direct toward, a common center; to unite more closely; to gather into one body, mass, or force; to fix; as, to concentrate rays of light into a focus; to concentrate the attention. [ 1913 Webster ]

(He) concentrated whole force at his own camp. Motley. [ 1913 Webster ]

2. To increase the strength and diminish the bulk of, as of a liquid or an ore; to intensify, by getting rid of useless material; to condense; as, to concentrate acid by evaporation; to concentrate by washing; -- opposed to dilute. [ 1913 Webster ]

Spirit of vinegar concentrated and reduced to its greatest strength. Arbuthnot.

Syn. -- To combine; to condense; to consolidate. [ 1913 Webster ]

adj. 1. Having a high density of (the indicated substance); as, a narrow thread of concentrated ore. [ Narrower terms: undiluted (vs. diluted) ] [ WordNet 1.5 ]

2. Gathered together or made less diffuse; as, their concentrated efforts; his concentrated attention. Opposite of distributed or diffused. [ Narrower terms: bunched, bunchy, clustered; centered, centred, centralized, focused; undivided ] [ Also See: compact. ] [ WordNet 1.5 ]

3. Intense; in an extreme degree; -- of mental phenomena; as, her concentrated passion held them at bay. [ WordNet 1.5 ]

4. being the most concentrated solution possible at a given temperature; unable to dissolve still more of a substance. Opposite of dilute or unsaturated. [ Narrower terms: supersaturated ]
Syn. -- saturated. [ WordNet 1.5 ]

5. reduced to a stronger or more concentrated form; as, concentrated sulfuric acid. Opposite of diluted.
Syn. -- condensed. [ WordNet 1.5 ]

6. characterized by intensity; especially when imposed from without; -- of actions; as, concentrated study.
Syn. -- intensive. [ WordNet 1.5 ]

7. characterized by mental concentration.
Syn. -- intent. [ WordNet 1.5 +PJC ]

n. [ Cf. F. concentration. ] 1. The act or process of concentrating; the process of becoming concentrated, or the state of being concentrated; concentration. [ 1913 Webster ]

Concentration of the lunar beams. Boyle. [ 1913 Webster ]

Intense concetration of thought. Sir J. Herschel. [ 1913 Webster ]

2. The act or process of reducing the volume of a liquid, as by evaporation. [ 1913 Webster ]

The acid acquires a higher degree of concentration. Knight. [ 1913 Webster ]

3. (Metal.) 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. [ 1913 Webster ]

a. Serving or tending to concentrate; characterized by concentration. [ 1913 Webster ]

A discrimination is only possible by a concentrative act, or act of attention. Sir W. Hamilton. [ 1913 Webster ]

n. 1. The quality of concentrating. [ 1913 Webster ]

2. (Phren.) The faculty or propensity which has to do with concentrating the intellectual the intellectual powers. Combe. [ 1913 Webster ]

n. (Mining) 1. An apparatus for the separation of dry comminuted ore, by exposing it to intermittent puffs of air. Knight.

2. (Firearms) A frame or ring of wire or hard paper fitting into the cartridge case used in some shotguns, and holding the shot together when discharged, to secure close shooting; also, a device for slightly narrowing the bore at the muzzle for the same purpose. [ Webster 1913 Suppl. ]