Source : Webster's Revised Unabridged Dictionary (1913)

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

Concentrate \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.

Source : WordNet®

concentrate
     n 1: the desired mineral that is left after impurities have been
          removed from mined ore [syn: {dressed ore}]
     2: a concentrated form of a foodstuff; the bulk is reduced by
        removing water
     3: a concentrated example; "the concentrate of contemporary
        despair"

concentrate
     v 1: make (the solvent of a solution) dense or denser
     2: direct one's attention on something; "Please focus on your
        studies and not on your hobbies" [syn: {focus}, {center},
        {centre}, {pore}, {rivet}]
     3: make central; "The Russian government centralized the
        distribution of food" [syn: {centralize}, {centralise}]
        [ant: {decentralize}, {decentralize}, {decentralize}]
     4: make more concise; "condense the contents of a book into a
        summary" [syn: {digest}, {condense}]
     5: draw together or meet in one common center; "These groups
        concentrate in the inner cities"
     6: compress or concentrate; "Congress condensed the three-year
        plan into a six-month plan" [syn: {condense}, {contract}]
     7: be cooked until very little liquid is left; "The sauce
        should reduce to one cup" [syn: {boil down}, {reduce}, {decoct}]
     8: cook until very little liquid is left; "The cook reduced the
        sauce by boiling it for a long time" [syn: {reduce}, {boil
        down}]