noun

• A carnivorous aquatic mammal in one of several families of order Cetacea, famed for its intelligence and occasional willingness to approach humans.
• Tursiops truncatus, (Atlantic bottlenose dolphin) the most well-known species.
• A fish, the mahi-mahi or dorado, Coryphaena hippurus, with a dorsal fin that runs the length of the body, also known for iridescent coloration.
• (heraldry) A depiction of a fish, with a broad indented fin, usually embowed.
• The dauphin, eldest son of the kings of France.
• (history) A mass of iron or lead hung from the yardarm, in readiness to be dropped through the deck and the hull of an enemy's vessel to sink it.
• (nautical) A kind of wreath or strap of plaited cordage.
• (nautical) A spar or buoy held by an anchor and furnished with a ring to which ships may fasten their cables.
• (nautical) A mooring post on a wharf or beach.
• (nautical) A permanent fender designed to protect a heavy boat or coastal structure from the impact of large floating objects such as ice or floating logs.
• (military, obsolete) One of the handles above the trunnions by which a gun was lifted.
• (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.
• A surname.
• A township in Knox County, Nebraska, United States.
• An unincorporated community in Brunswick County, Virginia, United States.
• An unincorporated community in San Juan County, Washington, United States.
• A member of an athletic team called the Dolphins, such as the Miami Dolphins and teams of various institutions of learning.