barnacle

A marine crustacean of the subclass Cirripedia that attaches itself to submerged surfaces such as tidal rocks or the bottoms of ships.

The barnacle goose.

(engineering, slang) In electrical engineering, a change made to a product on the manufacturing floor that was not part of the original product design.

(electronics, 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.

(software engineering, slang) A deprecated or obsolete file, image or other artifact that remains with a project even though it is no longer needed.

(obsolete, in the plural) 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.

(archaic, Britain, slang, in the plural) A pair of spectacles.

(slang, obsolete) A good job, or snack easily obtained.

(slang) A worldly sailor.