Source : Webster's Revised Unabridged Dictionary (1913)

Assimilate \As*sim"i*late\, v. i.
   1. To become similar or like something else. [R.]

   2. To change and appropriate nourishment so as to make it a
      part of the substance of the assimilating body.

            Aliment easily assimilated or turned into blood.
                                                  --Arbuthnot.

   3. To be converted into the substance of the assimilating
      body; to become incorporated; as, some kinds of food
      assimilate more readily than others.

            I am a foreign material, and cannot assimilate with
            the church of England.                --J. H.
                                                  Newman.

Assimilate \As*sim"i*late\, v. t. [imp. & p. p. {Assimilated};
   p. pr. & vb. n. {Assimilating}.] [L. assimilatus, p. p. of
   assimilare; ad + similare to make like, similis like. See
   {Similar}, {Assemble}, {Assimilate}.]
   1. To bring to a likeness or to conformity; to cause a
      resemblance between. --Sir M. Hale.

            To assimilate our law to the law of Scotland. --John
                                                  Bright.

            Fast falls a fleecy; the downy flakes Assimilate all
            objects.                              --Cowper.

   2. To liken; to compa?e. [R.]

   3. To appropriate and transform or incorporate into the
      substance of the assimilating body; to absorb or
      appropriate, as nourishment; as, food is assimilated and
      converted into organic tissue.

            Hence also animals and vegetables may assimilate
            their nourishment.                    --Sir I.
                                                  Newton.

            His mind had no power to assimilate the lessons.
                                                  --Merivale.

Source : WordNet®

assimilate
     v 1: take up mentally; "he absorbed the knowledge or beliefs of
          his tribe" [syn: {absorb}, {ingest}, {take in}]
     2: become similar to one's environment; "Immigrants often want
        to assimilate quickly" [ant: {dissimilate}]
     3: make similar; "This country assimilates immigrants very
        quickly" [ant: {dissimilate}]
     4: take (gas, light or heat) into a solution [syn: {imbibe}]
     5: become similar in sound; "The nasal assimialates to the
        following consonant" [ant: {dissimilate}]