The word "gastrodidymus" is a mouthful to spell, but understanding its pronunciation can make it easier. The word is pronounced [gæstrəʊˈdɪdəməs] and is broken down into several sounds. "Gastro-" refers to the stomach, pronounced [ˈgæstrəʊ]. "Didymus" means "twin" and is pronounced [ˈdɪdəməs]. Together, the word refers to an individual with two stomachs or a twin stomach. While it may be a complicated word to spell, knowing its pronunciation can make it easier to understand and remember.
A twin monster united at the abdomen which is common to both twins.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.