Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
Designating the part or surface of an echinoderm or other radiate animal which contains the mouth and surrounding organs (as the lower or oral side of a starfish); relating to this part.
Share your knowledge with the community
Browse our collection of 300,000+ community-written definitions
