accumulate - WordReference. com Dictionary of English ac•cu•mu•late (ə kyo̅o̅′ myə lāt′), v , -lat•ed, -lat•ing v t to gather or collect, often in gradual degrees; heap up: to accumulate wealth v i to gather into a heap, mass, cover, etc ; form a steadily increasing quantity: Snow accumulated in the driveway His debts kept on accumulating