the word cnidaria is spoken without the initial "c", and with a long "i". so it sounds like "naidaria". in a similar way, the term ctenophore is pronounced as "teenophore". originally, a greek kappa was in front of the words, and it was pronounced. the name comes from greek language "knidi", "nettle", thus mening "nettle-like animals" as all cnidarians have stinging cells like nettles.