To amass is to bring together materials that make a mass, a great bulk or quantity. With some occasional exceptions, accumulate is applied to the more more..To amass is to bring together materials that make a mass, a great bulk or quantity. With some occasional exceptions, accumulate is applied to the more gradual, amass to the more rapid gathering of money or materials, amass referring to the general result or bulk, accumulate to the particular process or rate of gain. We say interest is accumulated (or accumulates) rather than is amassed; he accumulated a fortune in the course of years; he rapidly amassed a fortune by shrewd speculations. Goods or money for immediate distribution are said to be collected rather than amassed. They may be stored up for a longer or shorter time; but to hoard is always with a view of permanent retention, generally selfish. Aggregate is now most commonly used of numbers and amounts; as, the expenses will aggregate a round million.(noun)