To collect into a mass or heap; to gather a great quantity of; to accumulate; as, to amass a treasure or a fortune; to amass words or phrases
he reluctantly returned to the old Nevada mines, there to recruit his health and to amass money enough to allow him to pursue his object without privation.
get or gather together; "I am accumulating evidence for the man's unfaithfulness to his wife"; "She is amassing a lot of data for her thesis"; "She rolled up a small fortune"
collect or gather; "Journals are accumulating in my office"; "The work keeps piling up"
If you amass something such as money or information, you gradually get a lot of it. How had he amassed his fortune? = accumulate, accrue. if you amass money, knowledge, information etc, you gradually collect a large amount of it (amasser, from masser )