ˌ ̷ ̷ ̷ ̷ ̷ ̷ or ̷ ̷ˌ ̷ ̷ ̷ ̷ at archae- +ˈsīəthə noun plural
Usage: capitalized
Etymology: New Latin, from Archaeocyathus
in some classifications : a phylum of extinct animals of uncertain systematic relations represented by fossils of the genus Archaeocyathus