barnacle

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of various marine crustaceans of the subclass Cirripedia that in the adult stage form a hard shell which remains attached to submerged surfaces such as rocks and ships' hulls, and that have feathery appendages used for filter feeding.
• noun The barnacle goose.

from The Century Dictionary.

• noun A species of wild goose, Anser bernicla or Bernicla leucopsis, also called barnacle-goose or bernacle-goose.
• noun 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).
• noun Anything resembling a barnacle (in sense 2).
• noun 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.
• noun [Cf. barnard.] A decoy swindler.
• noun 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.
• noun Hence An instrument of torture applied in a similar way to persons.
• noun plural Spectacles.
• To apply barnacles to: as, to barnacle a horse.
• To fix or attach, as a barnacle upon the bottom of a ship.

from the GNU version of the Collaborative International Dictionary of English.

• noun (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.
• noun (Zoöl.) the orange filefish.
• noun (Zoöl.) a bark louse (Ceroplastes cirripediformis) of the orange and quince trees in Florida. The female scale curiously resembles a sessile barnacle in form.
• noun A bernicle goose.
• noun (Far.) An instrument for pinching a horse's nose, and thus restraining him.
• noun Cant, Eng. Spectacles; -- so called from their resemblance to the barnacles used by farriers.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A marine crustacean of the subclass Cirripedia that attaches itself to submerged surfaces such as tidal rocks or the bottoms of ships.
• noun The barnacle goose.
• noun engineering, slang In electrical engineering, a change made to a product on the manufacturing floor that was not part of the original product design.
• noun 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.
• noun 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.
• noun archaic, UK A nickname for spectacles.
• noun slang, obsolete A good job, or snack easily obtained.
• verb To connect with or attach.
• verb To press close against something.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

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