barnacle

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of various marine crustaceans of the subclass Cirripedia that in the adult stage form a hard shell and remain attached to submerged surfaces, such as rocks and ships' bottoms.
2. n. The barnacle goose.

Century Dictionary and Cyclopedia

1. n. A species of wild goose, Anser bernicla or Bernicla leucopsis, also called barnacle-goose or bernacle-goose. It is one of several species of the genus Bernicla, inhabiting the northern parts of Europe, and occasionally appearing as a straggler in North America. It is smaller than the various wild geese of the genus Anser proper, has dark-brown or blackish upper parts, and a black neck and head, with large white patches. It is related to the common wild goose of North America, B. canadensis, and still more closely to the brent- or brant-goose, Bernicla brenta. This bird, which was known in the British islands only as a visitor, became the subject of a curious popular fable, not yet extinct, being believed to be bred from a tree growing on the sea-shore, either from the fruit of the tree or as itself the fruit (hence called tree-goose), or from a shell-fish which grew on this tree (see def. 2), or from rotting wood in the water.
2. n. A species of stalked cirriped, Lepas anatifera, of the family Lepadidæ, found hanging in clusters by the long peduncle to the bottoms of ships, to floating timber, or to submerged wood of any kind; the goose-mussel, fabled to fall from its support and turn into a goose (see def. 1). The name is sometimes extended or transferred to various other cirripeds, as the sessile acorn-shells or sea-acorns of the family Balanidæ, such as Balanus tintinnabulum. See Balanus. This is the usual sense of the word, except in Great Britain.
3. n. Anything resembling a barnacle (in sense 2). Any anomalous growth or extraneous adhering matter or arrangement tending to impede progress.
4. n. A person holding on tenaciously to a place or position; one who is a useless or incompetent fixture in an office or employment; a follower who will not be dismissed or shaken off.
5. n. [Cf. barnard.] A decoy swindler.
6. To fix or attach, as a barnacle upon the bottom of a ship.
7. n. A kind of bit or muzzle used to restrain an unruly horse or ass; now (usually in the plural), an instrument consisting of two branches joined at one end with a hinge, placed on a horse's nose to restrain him while being shod, bled, or dressed.
8. n. Hence An instrument of torture applied in a similar way to persons.
9. n. plural Spectacles.
10. To apply barnacles to: as, to barnacle a horse.

Wiktionary

1. n. A marine crustacean of the subclass Cirripedia that attaches itself to submerged surfaces such as tidal rocks or the bottoms of ships.
2. n. The barnacle goose.
3. n. engineering, slang In electrical engineering, a change made to a product on the manufacturing floor that was not part of the original product design.
4. n. computing, slang On printed circuit boards, a change such as soldering a wire in order to connect two points, or addition such as an added resistor or capacitor, subassembly or daughterboard.
5. n. obsolete An instrument like a pair of pincers, to fix on the nose of a vicious horse while shoeing so as to make it more tractable.
6. n. archaic, UK A nickname for spectacles.
7. n. slang, obsolete A good job, or snack easily obtained.
8. v. To connect with or attach.
9. v. To press close against something.

GNU Webster's 1913

1. n. (Zoöl.) Any cirriped crustacean adhering to rocks, floating timber, ships, etc., esp. (a) the sessile species (genus Balanus and allies), and (b) the stalked or goose barnacles (genus Lepas and allies). See cirripedia, and goose barnacle.
2. n. A bernicle goose.
3. n. (Far.) An instrument for pinching a horse's nose, and thus restraining him.
4. n. Cant, Eng. Spectacles; -- so called from their resemblance to the barnacles used by farriers.

WordNet 3.0

1. n. European goose smaller than the brant; breeds in the far north
2. n. marine crustaceans with feathery food-catching appendages; free-swimming as larvae; as adults form a hard shell and live attached to submerged surfaces