(ˌ)sīˌpəŋkyəˈlȯidēə noun plural
Usage: capitalized
Etymology: New Latin, from Sipunculus, genus of marine worms (from Latin sipunculus, siphunculus little pipe) + -oidea — more at siphuncle
1. : a group of marine worms of obscure systematic position that are commonly classed as a division of Gephyrea and that lack setae and have the mouth at the end of a retractile introvert similar to a proboscis and usually provided with tentacles and the anus anterior and dorsal
2. in some classifications
a. : a group coextensive with Gephyrea
b. : a class or other group comprising Sipunculoidea (sense 1) and Priapuloidea