en·ter·op·neus·ta I. \ˌ ̷ ̷ ̷ ̷ˌ ̷ ̷ˈn(y)üstə\noun plural Usage: capitalized Etymology: New Latin, from enter- + -pneusta : an order or other division of hemichordate worms consisting of Balanoglossus and related genera II. Etymology: New Latin, from enter- + -pneusta synonym of hemichordata