gudgeon

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A small Eurasian freshwater fish (Gobio gobio) related to the carp and used for bait.
2. n. Any of various similar or related fishes.
3. n. Slang One who is easily duped.
4. n. A metal pivot or journal at the end of a shaft or an axle, around which a wheel or other device turns.
5. n. The socket of a hinge into which a pin fits.
6. n. A metal pin that joins two pieces of stone.
7. n. Nautical The socket for the pintle of a rudder.

Century Dictionary and Cyclopedia

1. n. A small European fresh-water fish, Gobio fluviatilis, of the family Cyprinidœ. It is easily caught, and is used for bait. See cut under Gobio.
2. n. Hence A person easily cheated or insnared.
3. n. A bait; an allurement; something used to deceive or entrap a person; a cheat; a lie.
4. Resembling a gudgeon; foolish; stupid.
5. To insnare; cheat; impose on.
6. n. The large pivot of the axis of a wheel.
7. n. In machinery, that part of a horizontal shaft or axle which turns in the collar. The word formerly denoted the part revolving in immediate contact with the bearings. It is now applied only when that part is separate from and independent of the body of the shaft. The form of the gudgeon and the mode of its insertion depend upon the form and material of the shaft.
8. n. In ship-building: One of several clamps, of iron or other metal, bolted to the stern-post of a ship or boat for the rudder to hang on. There is a hole in each of them to receive a corresponding pintle bolted on the back of the rudder, which thus turns as upon hinges. There are generally 4, 5, or 6 gudgeons on a ship's stern-post, according to her size.
9. n. One of the notches in the carrick-bits for receiving the metal bushes in which the spindle of a windlass traverses.
10. n. A metallic pin used for securing together two blocks or slabs, as of stone or marble.
11. n. A piece of wood used for roofing.
12. n. Eleotris coxii, a gobioid fish of New South Wales.

Wiktionary

1. n. A small freshwater fish, Gobio gobio, that is native to Eurasia.
2. n. Any of various similar small fish of the family Eleotridae, often used as bait.
3. n. An idiot.
4. n. A type of bearing: a circular fitting, often made of metal, which is fixed onto some surface and allows for the pivoting of another fixture.
5. n. nautical Specifically, in a vessel with a stern-mounted rudder, the fitting into which the pintle of the rudder fits to allow the rudder to swing freely.
6. v. To deprive fraudulently; to cheat; to dupe.

GNU Webster's 1913

1. n. (Zoöl.) A small European freshwater fish (Gobio fluviatilis), allied to the carp. It is easily caught and often used for food and for bait. In America the killifishes or minnows are often called gudgeons.
2. n. What may be got without skill or merit.
3. n. A person easily duped or cheated.
4. n. (Mach.) The pin of iron fastened in the end of a wooden shaft or axle, on which it turns; formerly, any journal, or pivot, or bearing, as the pintle and eye of a hinge, but esp. the end journal of a horizontal.
5. n. (Naut.) A metal eye or socket attached to the sternpost to receive the pintle of the rudder.
6. v. rare To deprive fraudulently; to cheat; to dupe; to impose upon.

WordNet 3.0

1. n. small slender European freshwater fish often used as bait by anglers
2. n. small spiny-finned fish of coastal or brackish waters having a large head and elongated tapering body having the ventral fins modified as a sucker