Source : Webster's Revised Unabridged Dictionary (1913)

Need \Need\, v. t. [imp. & p. p. {Needed}; p. pr. & vb. n.
   {Needing}.] [See {Need}, n. Cf. AS. n?dan to force, Goth.
   nau?jan.]
   To be in want of; to have cause or occasion for; to lack; to
   require, as supply or relief.

         Other creatures all day long Rove idle, unemployed, and
         less need rest.                          --Milton.

   Note: With another verb, need is used like an auxiliary,
         generally in a negative sentence expressing requirement
         or obligation, and in this use it undergoes no change
         of termination in the third person singular of the
         present tense. ``And the lender need not fear he shall
         be injured.'' --Anacharsis (Trans. ).

Need \Need\, n. [OE. need, neod, nede, AS. ne['a]d, n[=y]d; akin
   to D. nood, G. not, noth, Icel. nau[eth]r, Sw. & Dan. n["o]d,
   Goth. naups.]
   1. A state that requires supply or relief; pressing occasion
      for something; necessity; urgent want.

            And the city had no need of the sun.  --Rev. xxi.
                                                  23.

            I have no need to beg.                --Shak.

            Be governed by your needs, not by your fancy. --Jer.
                                                  Taylor.

   2. Want of the means of subsistence; poverty; indigence;
      destitution. --Chaucer.

            Famine is in thy cheeks; Need and oppression
            starveth in thine eyes.               --Shak.

   3. That which is needful; anything necessary to be done;
      (pl.) necessary things; business. [Obs.] --Chaucer.

   4. Situation of need; peril; danger. [Obs.] --Chaucer.

   Syn: Exigency; emergency; strait; extremity; necessity;
        distress; destitution; poverty; indigence; want; penury.

   Usage: {Need}, {Necessity}. Necessity is stronger than need;
          it places us under positive compulsion. We are
          frequently under the necessity of going without that
          of which we stand very greatly in need. It is also
          with the corresponding adjectives; necessitous
          circumstances imply the direct pressure of suffering;
          needy circumstances, the want of aid or relief.

Need \Need\, v. i.
   To be wanted; to be necessary. --Chaucer.

         When we have done it, we have done all that is in our
         power, and all that needs.               --Locke.

Need \Need\, adv.
   Of necessity. See {Needs}. [Obs.] --Chaucer.

Source : WordNet®

need
     v 1: require as useful, just, or proper; "It takes nerve to do
          what she did"; "success usually requires hard work";
          "This job asks a lot of patience and skill"; "This
          position demands a lot of personal sacrifice"; "This
          dinner calls for a spectacular dessert"; "This
          intervention does not postulates a patient's consent"
          [syn: {necessitate}, {ask}, {postulate}, {require}, {take},
           {involve}, {call for}, {demand}] [ant: {obviate}]
     2: have need of; "This piano wants the attention of a competent
        tuner" [syn: {want}, {require}]
     3: have or feel a need for; "always needing friends and money"

need
     n 1: a condition requiring relief; "she satisfied his need for
          affection"; "God has no need of men to accomplish His
          work"; "there is a demand for jobs" [syn: {demand}]
     2: anything that is necessary but lacking; "he had sufficient
        means to meet his simple needs"; "I tried to supply his
        wants" [syn: {want}]
     3: the psychological feature that arouses an organism to action
        toward a desired goal; the reason for the action; that
        which gives purpose and direction to behavior; "we did not
        understand his motivation"; "he acted with the best of
        motives" [syn: {motivation}, {motive}]
     4: a state of extreme poverty or destitution; "their indigence
        appalled him"; "a general state of need exists among the
        homeless" [syn: {indigence}, {penury}, {beggary}, {pauperism},
         {pauperization}]