n. Nautical A vessel that is capable of operating submerged. Also called sub1.n. A large sandwich consisting of a long roll split lengthwise and filled with layers of meat, cheese, tomatoes, lettuce, and condiments. Also called sub1; also called regionally Cuban sandwich, grinder, hero, hoagie, Italian sandwich, poor boy, torpedo, wedge, zep.adj. Beneath the surface of the water; undersea.v. To attack by submarine, especially with torpedoes.v. Sports To knock down with a blow to the legs.v. Baseball To pitch (a ball) with an underhand motion.verb-intransitive. To slide, drive, or throw under something.