Nitric oxide (NO) Nitric oxide (NO), colourless, toxic gas that is formed by the oxidation of nitrogen. Though it has few industrial applications, nitric oxide performs important chemical signaling functions in humans and other animals and has various applications in medicine.
or British mollusc /ËmÉËlÉsk/. plural mollusks. Learner's definition of MOLLUSK. [count] biology. : any one of a large group of animals (such as snails and clams) that have a soft body without a backbone and that usually live in a shell.
Snails are mollusks belonging to the class Gastropoda, whose members, slugs and snails make up 80 percent of all mollusks. The gastropods live throughout the world, from the Arctic and Antarctic oceans to the equatorial regions. Also, some species have adaptations to survive in the water and some others on land. For their part, land snails are among the most widely distributed invertebrates around the world. They can be found on five continents and even in the sub-Antarctic region, where temperatures are very low.