percolate

bubble, foam, froth, head, spume, lather, suds, spray, surf, yeast, barm, spindrift., cloud, vapor, fog, mist, haze, steam, geyser; scud, messenger, rack, nimbus; cumulus, woolpack, cirrus, stratus; cirrostratus, cumulostratus; cirrocumulus; mackerel sky, mare's tale, dirty sky; curl cloud; frost smoke; thunderhead., [Science of clouds] nephelognosy; nephograph, nephology., effervescence, fermentation; bubbling., nebula; cloudliness (opacity); nebulosity (dimness).