Con*cen"trate (? or ?), 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.

(He) concentrated whole force at his own camp.
Motley.

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.

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

Syn. -- To combine; to condense; to consolidate.

Con*cen"trate (? or ?), v. i. To approach or meet in a common center; to consolidate; as, population tends to concentrate in cities.

• 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.
  
• 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.
  
• To approach or meet in a common center; to consolidate; as, population tends to concentrate in cities.