The word "epitoxoid" is quite uncommon, and its spelling may seem daunting at first glance. However, breaking it down into its phonetic components can demystify its spelling. According to the International Phonetic Alphabet (IPA), "epitoxoid" is pronounced /ɛpɪˈtɑksɔɪd/. This can be read as "eh-pih-TAHK-soyd." The word appears to be of scientific or technical origin, as it contains the suffix "-oid," which is often used in the names of chemical or biological compounds.
A toxoid having a weaker affinity for an antitoxin than has the toxin; a toxon.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.