æsˈsiːdiəm

Definitions

1. noun

A type of marine animal, specifically a member of the phylum Chordata, class Ascidiacea, and characterized by a sac-like body with a network of siphons and a notochord.

“The marine biologist studied the unique life cycle of ascidiums in the ocean.”

2. noun

A type of coral or other marine structure resembling an ascidium in shape.

“The diver swam past a large ascidium formation in the coral reef.”