annelid – soft bodied, with numerous segments

(pronounced ah-nuh-lid)

Note: The best example of annelids are leeches and earthworms. 

Note: Earthworms and round worms while both classified as "worms", are fundamentally different, earthworms are segmented worms belonging to the phylum Annelida, while roundworms are non-segmented worms of the phylum Nematoda.

To remember the meaning of annelid, associate annelid to leeches and use that mnemonic, to remember annelids are soft bodies with numerous segments use the following mnemonic:

On an eyelid (annelid) sat a leech. 

Annelids have soft bodies that are divided into numerous ring-like segments. This diverse group includes earthworms, marine worms and leeches, all of which share key characteristics such as a closed circulatory system (contained within arteries and blood vessels) and a well developed nervous system with a brain and nerve chord. 

The segmented body allows for efficient movement as muscles in each segment can contract independently, enabling the characteristic crawling motion seen in earthworms. Most annelids have bristle-like structures on their bodies which help with movement and gripping surfaces.

Annelids play important ecological roles, with earthworms being crucial for soil health as they decompose organic matter and aerate soil, while marine worms serve as important food sources in ocean ecosystems, some filter feed to help clean water.