accretion

1 a mass or quantity that has piled up or that has been gathered over a period of time a thick accretion of ice in a freezer that obviously had not been cleaned for some time Synonyms accumulation, assemblage, collection, cumulation, cumulus, gathering, lodgment (or lodgement), pileupRelated Words agglomerate, assortment, congeries, conglomerate, conglomeration, hodgepodge, hotchpotch, jumble, medley, mélange, mishmash, mix, mixture, motley, potpourri; agglomeration, clutter, hash, heap, litter, mass, pile; aggregate, aggregation, sum, totality; backlog, cache, fund, hoard, inventory, kitty, nest egg, reserve, stock, stockpile, store, supply

2 something added (as by growth) accretions of lime have thickened the cave's stalactites and stalagmites over the centuries Synonyms increase, accrual, addendum, addition, augmentation, boost, expansion, gain, increment, more, plus, proliferation, raise, rise, step-up, supplement, uptickRelated Words accumulation, assemblage, collection, gathering; complement; accession, appendix, continuation, extension, uptrend, upturn; jump, run-up, spikeNear Antonyms deduction, subtractionAntonyms abatement, decline, decrease, decrement, depletion, diminishment, diminution, drop-off, fall, falloff, lessening, loss, lowering, reduction, shrinkage, step-down