As "Supercalifragalisticexpialidocious" isn't really a word, I don't think you can really expect it to have a rhyme. However, try finding something that rhymes with "cious" as a syllable rather than the whole word, and you might come up with something fairly constructive.
Cerberus rhymes with:what-rhymes-with-arras-rhymes, what-rhymes-with-embarrass-rhymes, what-rhymes-with-harass-rhymeswhat-rhymes-with-gynandrous-rhymes, what-rhymes-with-polyandrous-rhymeswhat-rhymes-with-pancras-rhymes, what-rhymes-with-charas-rhymes, what-rhymes-with-tatras-rhymes, what-rhymes-with-disastrous-rhymeswhat-rhymes-with-ferrous-rhymes, what-rhymes-with-leprous-rhymes, what-rhymes-with-ambidextrous-rhymeswhat-rhymes-with-carreras-rhymes, what-rhymes-with-mayoress-rhymeswhat-rhymes-with-scabrous-rhymeswhat-rhymes-with-cirrus-rhymes, what-rhymes-with-pyrrhus-rhymeswhat-rhymes-with-chivalrous-rhymeswhat-rhymes-with-citrous-rhymes, what-rhymes-with-citrus-rhymeswhat-rhymes-with-ludicrous-rhymes, what-rhymes-with-tenebrous-rhymeswhat-rhymes-with-cyrus-rhymes, what-rhymes-with-epirus-rhymes, what-rhymes-with-papyrus-rhymes, what-rhymes-with-virus-rhymeswhat-rhymes-with-fibrous-rhymes, what-rhymes-with-hydrous-rhymes, what-rhymes-with-cyprus-rhymeswhat-rhymes-with-retrovirus-rhymes, what-rhymes-with-monstrous-rhymeswhat-rhymes-with-brachiosaurus-rhymes, what-rhymes-with-brontosaurus-rhymes, what-rhymes-with-canorous-rhymes, what-rhymes-with-chorus-rhymes, what-rhymes-with-epidaurus-rhymes, what-rhymes-with-horus-rhymes, what-rhymes-with-megalosaurus-rhymes, what-rhymes-with-pelorus-rhymes, what-rhymes-with-porous-rhymes, what-rhymes-with-sorus-rhymes, what-rhymes-with-stegosaurus-rhymes, what-rhymes-with-taurus-rhymes, what-rhymes-with-thesaurus-rhymes, what-rhymes-with-torus-rhymes, what-rhymes-with-tyrannosaurus-rhymeswhat-rhymes-with-walrus-rhymeswhat-rhymes-with-ochrous-rhymes(US ocherous)what-rhymes-with-cumbrous-rhymes, what-rhymes-with-wondrous-rhymes, what-rhymes-with-lustrous-rhymeswhat-rhymes-with-algeciras-rhymes, what-rhymes-with-severus-rhymeswhat-rhymes-with-desirous-rhymeswhat-rhymes-with-arcturus-rhymes, what-rhymes-with-epicurus-rhymes, what-rhymes-with-honduras-rhymeswhat-rhymes-with-barbarous-rhymes, what-rhymes-with-tuberous-rhymes, what-rhymes-with-slumberous-rhymesCerberus , what-rhymes-with-rapturous-rhymeswhat-rhymes-with-lecherous-rhymes, what-rhymes-with-treacherous-rhymeswhat-rhymes-with-torturous-rhymes, what-rhymes-with-vulturous-rhymes, what-rhymes-with-pandarus-rhymeswhat-rhymes-with-slanderous-rhymes, what-rhymes-with-ponderous-rhymeswhat-rhymes-with-malodorous-rhymes, what-rhymes-with-odorous-rhymeswhat-rhymes-with-thunderous-rhymes, what-rhymes-with-murderous-rhymeswhat-rhymes-with-carboniferous-rhymes, what-rhymes-with-coniferous-rhymes, what-rhymes-with-cruciferous-rhymes, what-rhymes-with-melliferous-rhymes, what-rhymes-with-odoriferous-rhymes, what-rhymes-with-pestiferous-rhymes, what-rhymes-with-somniferous-rhymes, what-rhymes-with-splendiferous-rhymes, what-rhymes-with-umbelliferous-rhymes, what-rhymes-with-vociferous-rhymeswhat-rhymes-with-phosphorous-rhymes, what-rhymes-with-phosphorus-rhymeswhat-rhymes-with-sulphurous-rhymes(US sulfurous)what-rhymes-with-anaxagoras-rhymes, what-rhymes-with-pythagoras-rhymeswhat-rhymes-with-clangorous-rhymes, what-rhymes-with-languorous-rhymeswhat-rhymes-with-rigorous-rhymes, what-rhymes-with-vigorous-rhymeswhat-rhymes-with-dangerous-rhymes, what-rhymes-with-verdurous-rhymeswhat-rhymes-with-cankerous-rhymes, what-rhymes-with-cantankerous-rhymes, what-rhymes-with-rancorous-rhymeswhat-rhymes-with-decorous-rhymes, what-rhymes-with-icarus-rhymes, what-rhymes-with-valorous-rhymeswhat-rhymes-with-dolorous-rhymes, what-rhymes-with-idolatrous-rhymeswhat-rhymes-with-amorous-rhymes, what-rhymes-with-clamorous-rhymes, what-rhymes-with-glamorous-rhymeswhat-rhymes-with-timorous-rhymeswhat-rhymes-with-humerus-rhymes, what-rhymes-with-humorous-rhymes, what-rhymes-with-numerous-rhymeswhat-rhymes-with-murmurous-rhymes, what-rhymes-with-generous-rhymes, what-rhymes-with-sonorous-rhymeswhat-rhymes-with-onerous-rhymes, what-rhymes-with-obstreperous-rhymes, what-rhymes-with-hesperus-rhymeswhat-rhymes-with-vaporous-rhymes, what-rhymes-with-viviparous-rhymes, what-rhymes-with-viperous-rhymeswhat-rhymes-with-bosporus-rhymes, what-rhymes-with-prosperous-rhymeswhat-rhymes-with-stuporous-rhymes, what-rhymes-with-cancerous-rhymeswhat-rhymes-with-monoceros-rhymes, what-rhymes-with-rhinoceros-rhymeswhat-rhymes-with-sorcerous-rhymes, what-rhymes-with-adventurous-rhymes, what-rhymes-with-tartarus-rhymeswhat-rhymes-with-nectarous-rhymes, what-rhymes-with-dexterous-rhymes, what-rhymes-with-traitorous-rhymeswhat-rhymes-with-preposterous-rhymes, what-rhymes-with-slaughterous-rhymeswhat-rhymes-with-boisterous-rhymes, what-rhymes-with-roisterous-rhymeswhat-rhymes-with-uterus-rhymes, what-rhymes-with-adulterous-rhymes, what-rhymes-with-stertorous-rhymeswhat-rhymes-with-cadaverous-rhymes, what-rhymes-with-feverous-rhymeswhat-rhymes-with-carnivorous-rhymes, what-rhymes-with-herbivorous-rhymes, what-rhymes-with-insectivorous-rhymes, what-rhymes-with-omnivorous-rhymeswhat-rhymes-with-lazarus-rhymes
Toy rhymes with joy but I don't know what rhymes with saturn
Rhymes with argument:ApartmentCompartmentDebarmentDepartmentDisbarmentFraudulentGarmentVarmintWarrant
rhymes
daises rhymes with praises
rhymes with nothing
no perfect rhymes, but for near rhymes try words that end with our.
University rhymes with diversity.
dance rhymes with glance cancer rhymes with dancer
It rhymes with no mess.
Loudly rhymes with proudly.
There is no word that rhymes with vertical.