We don't have synonyms for cnidarians yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are cnidaria, cnidarian and unitarians.
(n) :
(zoology) Any of various invertebrate animals, such as jellyfish, hydras, sea anemones, corals and formerly sponges and ctenophores that belong to the phylum Cnidaria.
(n) :
(zoology) Any of various invertebrate animals, such as jellyfish, hydras, sea anemones, corals and formerly sponges and ctenophores that belong to the phylum Cnidaria.