coracidium

noun
cor·​a·​cid·​i·​um | \ ˌkȯr-ə-ˈsid-ē-əm How to pronounce coracidium (audio) \
plural coracidia\ -​dē-​ə How to pronounce coracidia (audio) \

Medical Definition of coracidium

: the oncosphere of a tapeworm at about the time of hatching while still surrounded by the embryophore