dolphin

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of various marine cetacean mammals, such as the bottle-nosed dolphin, of the family Delphinidae, related to the whales but generally smaller and having a beaklike snout.
2. n. A large marine food and game fish (Coryphaena hippurus) found worldwide in tropical waters, having an iridescent blue back, yellow sides, a steep blunt forehead, and a long continuous dorsal fin. Also called dolphinfish, dorado, mahi-mahi.
3. n. A similar fish (C. equisetis) of smaller size, having silvery or pale yellow sides. Also called dolphinfish, pompano dolphin.
4. n. A buoy, pile, or group of piles used for mooring boats.
5. n. A group of piers used as a fender at a dock.

Century Dictionary and Cyclopedia

1. n. The popular name of the cetaceous mammals of the family Delphinidæ and genus Delphinus, most of which are also known as and more frequently called porpoises, this word being interchangeable with dolphin. The dolphin proper is Delphinus delphis, having a longer and sharper snout than the porpoise proper, divided by a constriction with convexity forward from the convex forehead. It abounds in the Mediterranean and the temperate parts of the Atlantic, is an agile animal, and often follows ships in large herds, executing amusing gambols, describing semicircular curves which bring the blow-hole out of water to enable itself to breathe. A usual length is about 6 feet.
2. n. A general and popular name of fish of the family Coryphænidæ: so called from some con-fusion with the mammals of the same name. Species are Coryphæna hippurus, C. equisetis, etc., of an elongated antrorsiform shape with a high protuberant forehead and very long dorsal fin, inhabiting the high seas of warm and temperate latitudes. They range up to 5 or 6 feet in length, and are remarkable for the change of color they undergo when taken out of the water. Also called dorado. See cut under Coryphæna.
3. n. In Gr. antiquity, a ponderous mass of lead or iron suspended from a special yard on a naval vessel, and, if opportunity presented, let fall into the hold of a hostile ship to sink her by breaking through her bottom.
4. n. Nautical: A spar or buoy made fast to an anchor, and usually supplied with a ring to enable vessels to ride by it.
5. n. A mooring-post placed at the entrance of a dock. It is generally composed of a series of piles driven near to one another in a circle, and brought together and capped over at the top. The name is also sometimes applied to the mooring-posts placed along a quay or wharf.
6. n. In early artillery, a handle cast solid on a cannon. Usually two of these were placed at the balancing-point, so that the gun would hang horizontal if suspended by them. They were commonly made in the conventional form of a dolphin; hence the name.
7. n. [capitalized] In astronomy, an ancient northern constellation, Delphinus (which see).
8. n. In architecture, a technical term applied to the pipe and cover at a source for the supply of water.
9. n. In Christian archæol., an image or representation of a dolphin, constituting an emblem of love, diligence, and swiftness. It was frequently introduced in architectural sculpture, etc., or worn as an ornament by the early Christians. It was often represented entwined about an anchor.
10. n. Same as dauphin.
11. n. In lumbering, a cluster of piles to which a boom is secured. [U. S.]
12. n. Same as dolphin-fly.

Wiktionary

1. n. A carnivorous aquatic mammal inhabiting mostly in the shallower seas of the continental shelves, famed for its intelligence and occasional willingness to approach humans.
2. n. A fish, the mahi-mahi or dorado, scientific name Coryphaena hippurus, with a dorsal fin that runs the length of the body, also known for iridescent coloration.
3. n. The dauphin, eldest son of the kings of France.
4. n. nautical A man-made semi submerged maritime structure, usually installed to provide a fixed structure for temporary mooring, to prevent ships from drifting to shallow water or to serve as base for navigational aids.

GNU Webster's 1913

1. n. (Zool.) A cetacean of the genus Delphinus and allied genera (esp. Delphinus delphis); the true dolphin.
2. n. (Zool.) The Coryphæna hippuris, a fish of about five feet in length, celebrated for its surprising changes of color when dying. It is the fish commonly known as the dolphin. The term is also applied to the related Coryphaena equisetis. Called also dolphinfish and (especially in Hawaii) mahimahi. See also dolphinfish and Coryphænoid.
3. n. (Gr. Antiq.) A mass of iron or lead hung from the yardarm, in readiness to be dropped on the deck of an enemy's vessel.
4. n. A kind of wreath or strap of plaited cordage.
5. n. A spar or buoy held by an anchor and furnished with a ring to which ships may fasten their cables.
6. n. A mooring post on a wharf or beach.
7. n. A permanent fender around a heavy boat just below the gunwale.
8. n. (Gun.) In old ordnance, one of the handles above the trunnions by which a cannon was lifted.
9. n. (Astron.) A small constellation between Aquila and Pegasus. See Delphinus, n., 2.

WordNet 3.0

1. n. any of various small toothed whales with a beaklike snout; larger than porpoises
2. n. large slender food and game fish widely distributed in warm seas (especially around Hawaii)