To gather or collect, often in gradual degrees; heap up (Dictionary.com).
From L. cumulatus "heaped, increased, augmented," p.p. of cumulare "to heap," from cumulus "mound, heap," from PIE *ku-m-olo-, from *keue- "to swell;" cf. Skt. śavi "to swell;" svayati "swells up, is strong;" Av. su-, sauu- "to bulge, swell up, increase;" Proto-Ir. *sauH- "to bulge, swell up, increase" (Cheung 2007, Pers. sud "gain, profit"); Gk. kuein "to swell;" Lith. saunas.
Kumidan, from kum, kumé "heap;" Hamedâni kumelé, kumelân "heap, pile, mound," kumé kardan "to accumulate;" Kurd. kom "pile, group," komel "society, organization," related to Pers. kud "heap" (Mid.Pers. kôt), Gilaki kô-pâ "warehouse, barn," kô-gâh "gathering site." In the Gilan province there are several localities with protruding positions that bear names with an initial kom- (such as komâcâl, komâdol, kumélé, komsâr, etc.); probably related to L. cumul-, as above; if confirmed, interestingly it relates to the PIE form *keue- in contrast with Proto-Ir. *sauH-, as above.