Synonyms for Accumulation:

n.

backlog, block, quantity, balance, pile, allowance, batch, amount, capacity, mass, arithmetic, allocation, heap. congeries, Cumulation, collect. accumulation (noun)
accretion, aggregation, accrual, assemblage, collection, accruement.
acquisition (noun)
assumption, appropriation, catch, claim, gain, annexation, purchase, collection, procurement.
addition (noun)
enlargement, attainment, expansion, acquisition, increment, increase, aggregation, accrual, addition, augmentation.
gathering or amassing (noun)
quantity, mass, inflation, aggregation, accretion, collection, heap, enlargement, augmentation, multiplication, increase, addition, Amassment, store, growth, accession, pile, agglomeration.
store (noun)
crib, grocery, cellar, depot, larder, coffer, buttery, market, archive, bank, depository, lumberyard, library, supermarket, locker, store, cache, armory, commissary, hoard, hayloft, granary, storehouse, silo, arsenal, mart, repository, stockpile, storeroom, closet, cupboard, Corncrib, treasure, bin, storage, safe, warehouse, emporium, vault.
supply (noun)
stockpile.

Other synonyms:

arithmetic, recovery, buildup, allowance, Cumulation, amount, Amassment. batch, quantity, balance, retrieval. capacity, round up, block. capture, mass. pile
congeries, heap.
reserve
backlog.
Other relevant words:
balance, buildup, mass, multiplication, congeries, accretion, batch, collect, inflation, backlog, Amassment, amount, accession, growth, retrieval, recovery, block, assemblage, arithmetic, capacity, quantity, agglomeration, Cumulation, heap, capture, pile, accruement.

Usage examples for accumulation

  1. She never gave out to let me see any result of all this accumulation of musical knowledge which I knew she possessed, never asking a question or advancing any question or enthusiastic outburst of expression. – Sixty Years of California Song by Margaret Blake-Alverson