Source : Webster's Revised Unabridged Dictionary (1913)

Differentiate \Dif`fer*en"ti*ate\, v. i. (Biol.)
   To acquire a distinct and separate character. --Huxley.

Differentiate \Dif`fer*en"ti*ate\, v. t.
   1. To distinguish or mark by a specific difference; to effect
      a difference in, as regards classification; to develop
      differential characteristics in; to specialize; to
      desynonymize.

            The word then was differentiated into the two forms
            then and than.                        --Earle.

            Two or more of the forms assumed by the same
            original word become differentiated in
            signification.                        --Dr. Murray.

   2. To express the specific difference of; to describe the
      properties of (a thing) whereby it is differenced from
      another of the same class; to discriminate. --Earle.

   3. (Math.) To obtain the differential, or differential
      coefficient, of; as, to differentiate an algebraic
      expression, or an equation.

Source : WordNet®

differentiate
     v 1: mark as different; "We distinguish several kinds of maple"
          [syn: {distinguish}, {separate}, {secern}, {secernate},
          {severalize}, {severalise}, {tell}, {tell apart}]
     2: be a distinctive feature, attribute, or trait; sometimes in
        a very positive sense; "His modesty distinguishes him form
        his peers" [syn: {distinguish}, {mark}]
     3: calculate a derivative; take the derivative [ant: {integrate}]
     4: become different during development; "cells differentiate"
        [ant: {dedifferentiate}]
     5: evolve so as to lead to a new species or develop in a way
        most suited to the environment [syn: {speciate}, {specialize},
         {specialise}]
     6: become distinct and acquire a different character