Source : Webster's Revised Unabridged Dictionary (1913)

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.

Source : WordNet®

accumulated
     adj 1: brought together into a group or crowd; "the accumulated
            letters in my office" [syn: {amassed}, {assembled}, {collected},
             {congregate}, {massed}]
     2: periodically accumulated over time; "accrued interest";
        "accrued leave" [syn: {accrued}]