Source : Webster's Revised Unabridged Dictionary (1913)

Accumulate \Ac*cu"mu*late\ (-l[asl]t), a. [L. accumulatus, p. p.
   of accumulare.]
   Collected; accumulated. --Bacon.

Accumulate \Ac*cu"mu*late\, v. t. [imp. & p. p. {Accumulated};
   p. pr. & vb. n. {Accumulating}.] [L. accumulatus, p. p. of
   accumulare; ad + cumulare to heap. See {Cumulate}.]
   To heap up in a mass; to pile up; to collect or bring
   together; to amass; as, to accumulate a sum of money.

   Syn: To collect; pile up; store; amass; gather; aggregate;
        heap together; hoard.

Accumulate \Ac*cu"mu*late\ ([a^]k*k[=u]"m[-u]*l[=a]t), v. i.
   To grow or increase in quantity or number; to increase
   greatly.

         Ill fares the land, to hastening ills a prey, Where
         wealth accumulates, and men decay.       --Goldsmith.

Source : WordNet®

accumulate
     v 1: get or gather together; "I am accumulating evidence for the
          man's unfaithfulness to his wife"; "She is amassing a
          lot of data for her thesis"; "She rolled up a small
          fortune" [syn: {roll up}, {collect}, {pile up}, {amass},
           {compile}, {hoard}]
     2: collect or gather; "Journals are accumulating in my office";
        "The work keeps piling up" [syn: {cumulate}, {conglomerate},
         {pile up}, {gather}, {amass}]