mьgla > Russian мгла (mgla), Polish mgła, Czech mlha, Slovak hmla, Ukrainian імла (imla), "mist". The English word is also cognate, as is the Sanskrit मेघ...

chmura, obłok oblak oblák облак oblak fog *mьglà мгла, туман mgla, tuman імла, туман, мряковина imlá, tumán, mr'ákovyna мъгла́ mǝglá mlha hmla mgła magla...