adjective
Definition: Relating to a group of marine worms known for their long, slender bodies and ability to extend and retract.
Example: The nemertean species found in the ocean can vary greatly in size and color.
noun
Definition: A type of long, flat marine worm that is often brightly colored and has a special feeding structure called a proboscis. These worms usually live in the sea or in muddy areas near the shore.
Example: The nemertean was spotted crawling along the sandy beach, its vibrant colors shining in the sunlight.