Hydrous rhymes with:
ambassadress, andras, andrus, cassandras, landrus, madras, polyandrous, wondrous, actress, adenovirus, ahasuerus, alturas, ambassadress, ambidextrous, andras, andrus, arcturus, arris, assuras, barrus, beatrice, belarus, brontosaurus, burrus, burruss, buttress, calveras, cassandras, cerus, chorus, cirrus, citrus, congress, cypress, cyprus, cyrus, cytomegalovirus, damaris, debrosse, derose, desirous, dextrous, dilophosaurus, disastrous, doris, duross, dyloptisaurus, elbrus, embarrass, estrous, estrus, febres, ferrous, fibrous, fortress, gavras, goris, hantavirus, headmistress, heiress, honduras, horace, horus, hubris, idolatrous, iris, jerris, kontras, kupres, landrus, lesabres, ludicrous, lustrous, madras, malphrus, maquiladoras, marous, mattress, maurus, mcdaris, mcmorris, meris, mistress, monstrous, morris, morris', nitrous, nonferrous, ogress, peatross, pendergrass, peras, petrobras, petrus, pharis, polaris, polyandrous, porous, pythagorus, retrovirus, sampras, sampras', sentras, sorus, stegosaurus, taurus, tenebrous, terrace, thesaurus, tigris, torras, tyrannosaurus, virus, waitress, walrus, watrous, wondrous
Hydrous sounds like:
haters, hatrick, hatteras, headdress, headdresses, headers, headrick, headwaters, heaters, heather's, heathers, heathrow's, hedrich, hedrick, heidrich, heidrick, heterosis, heterozygous, hetrick, hettrick, hitters, hooters, hydras, hydrick, hydro's, hydrox, hydroxy