The word "precipitoid" is a relatively new addition to the English language. It refers to a substance that can cause precipitation. The pronunciation of "precipitoid" is /prɪˈsɪpɪtɔɪd/. The first part of the word, "prɪ", rhymes with "fizz". The second part, "-sipit-", is pronounced with a short "i" sound, like "sitting". The final part, "-ɔɪd", rhymes with "avoid". While the spelling may seem daunting at first, breaking it down phonetically can make it easier to remember and pronounce.
A precipitin which has lost its labile precipitophore group; it has the power of binding precipitogen but not of forming a precipitate.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.