Source : Webster's Revised Unabridged Dictionary (1913)

Benefit \Ben"e*fit\, v. i.
   To gain advantage; to make improvement; to profit; as, he
   will benefit by the change.

Benefit \Ben"e*fit\, n. [OE. benefet, benfeet, bienfet, F.
   bienfait, fr. L. benefactum; bene well (adv. of bonus good) +
   factum, p. p. of facere to do. See {Bounty}, and {Fact}.]
   1. An act of kindness; a favor conferred.

            Bless the Lord, O my soul, and forget not all his
            benefits.                             --Ps. ciii. 2.

   2. Whatever promotes prosperity and personal happiness, or
      adds value to property; advantage; profit.

            Men have no right to what is not for their benefit.
                                                  --Burke.

   3. A theatrical performance, a concert, or the like, the
      proceeds of which do not go to the lessee of the theater
      or to the company, but to some individual actor, or to
      some charitable use.

   4. Beneficence; liberality. [Obs.] --Webster (1623).

   5. pl. Natural advantages; endowments; accomplishments. [R.]
      ``The benefits of your own country.'' --Shak.

   {Benefit of clergy}. (Law) See under {Clergy}.

   Syn: Profit; service; use; avail. See {Advantage}.

Benefit \Ben"e*fit\, v. t. [imp. & p. p. {Benefited}; p. pr. &
   vb. n. {Benefitting}.]
   To be beneficial to; to do good to; to advantage; to advance
   in health or prosperity; to be useful to; to profit.

         I will repent of the good, wherewith I said I would
         benefit them.                            --Jer. xviii.
                                                  10.

Source : WordNet®

benefit
     n 1: financial assistance in time of need
     2: something that aids or promotes well-being; "for the common
        good" [syn: {welfare}]
     3: a performance to raise money for a charitable cause
     [also: {benefitting}, {benefitted}]

benefit
     v 1: derive a benefit from; "She profited from his vast
          experience" [syn: {profit}, {gain}]
     2: be beneficial for; "This will do you good" [syn: {do good}]
     [also: {benefitting}, {benefitted}]