The word "hystereurynter" is a medical term that refers to the dilation of the uterus. The spelling of this word can be quite intimidating, but it can be broken down using the International Phonetic Alphabet (IPA). The first syllable "hys" is pronounced as /hɪs/ followed by "tere" which is pronounced as /ˈtɛr/. The final syllables "urynter" are pronounced as /yˈrɪntər/. Altogether, the word is pronounced as /hɪsˌtɛrjʌˈrɪntər/. Understanding the IPA phonetic transcription makes it easier to tackle difficult words like "hystereurynter".
Metreurynter, an instrument, such as Barnes's bag, for dilating the os uteri.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.