這兩個形容詞均意為「累積的；漸增的」，但它們只是部分同義詞，因為一般而言，accumulative 含有「鑽鑽營營；貪得無厭；利慾薰心」(acquisitiveness) 的言外之意，如 He has accumulative drives for fame and money. (他對名利的慾望與日俱增)；We live in an accumulative society. (我們生活在一個貪得無厭的社會)，或暗示一個人具有好積聚、好收藏的個性，如 Her accumulative energies are unflagging; she is one of the great collectors. (她蓄積的能量歷久不衰；她是偉大的收藏家之一)。
Cumulative 通常沒有貶抑的含意，如 the cumulative total (累計總額；累積總數)； a cumulative effect (累積效應；蓄積作用)；At the end of October, the cumulative total (number) of reported H1N1 cases was more than 100. (在10月底，已呈報的新流感個案已累積至逾 100 件)；He believes the ad campaign will eventually be successful and will have a positive cumulative effect on sales volume. (他相信廣告活動終將成功，銷售量也會正面地逐步增長)。a cumulative effect 亦可寫成 an accumulative effect，但後者相當少用。