Most creatures known as sea slugs are actually snails, i.e. they are sea snails (marine gastropod mollusks) that over evolutionary time have lost their shells, or have a greatly reduced shell or an internal shell. sea cucumber also looks slug-like and is sometimes loosely called a sea slug, but it is not a gastropod. Sea slug is a common name which is applied to some marine invertebrates that more or less resemble terrestrial slugs.
Medical Definition of VERTEBRA. : any of the bony or cartilaginous segments that make up the spinal column and that have a short more or less cylindrical body whose ends articulate by pads of elastic or cartilaginous tissue with those of adjacent vertebrae and a bony arch that encloses the spinal cord.ord Root of VERTEBRA. The Latin word vertere, meaning â to turn â or â to change, â and its form versus give us the roots vert and vers. Words from the Latin vertere have something to do with turning or changing.
neck. 1  that part of a human or animal joining the head to the body, including the part of the backbone between the skull and the shoulders. 2  a narrow part between the head, or end, and the body, or base, of any object: the neck of a violin, the neck of a goblet.