n.
One of the numerous external, fluid-filled muscular tubes of echinoderms, such as the starfish or sea urchin, serving as organs of locomotion, food handling, and respiration.
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
