/huy ol"i thid/ , n.
1. any invertebrate of the extinct genus Hyolithes, most common in the Cambrian Period, having a limy, univalve shell, and thought to be related to the pteropods.
adj.
2. belonging or pertaining to Hyolithes.
[ Hyolith ( es ) (see HYOID, -LITH) + -ID 2 ]