adapter

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

• noun One that adapts, such as a device used to effect operative compatibility between different parts of one or more pieces of apparatus.

from The Century Dictionary.

• noun In photography, an attachment to a camera by means of which plates of sizes other than those for which the camera is designed may be used.
• noun One who adapts, or makes an adaptation; specifically, one who translates, remodels, or rearranges a composition or work, rendering it fit to be represented on the stage, as a play from a foreign tongue or from a novel.
• noun That which adapts; anything that serves the purpose of adapting or adjusting one thing to another. Specifically
• noun In chem., a receiver with two necks diametrically opposite, one of which admits the neck of a retort, while the other is joined to a second receiver.
• noun In optics: A metal ring uniting two lengths of a telescope.
• noun An attachment to a microscope for centering the illuminating apparatus or throwing it out of center. E. H. Knight.
• noun A means for enabling object-glasses made by different makers, and having different screws, to be fitted to a body not specially adapted to receive them.
• noun A glass or rubber tube, with ends differing in size, used to connect two other tubes or two pieces of apparatus.

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

• noun One who adapts.
• noun (Chem.) A connecting tube; an adopter.

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

• noun One who is capable of adapting well to differing situations.
• noun One who adapts a thing, e.g. a play.
• noun A device or application used to achieve operative compatibility between devices that otherwise are incompatible.
• noun Specifically, a device that permits two, three, or more plugs to be used at a single electrical power point.
• noun Specifically, a device that allows one format of plug to be used with a different format of socket.

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

• noun a musician who adapts a composition for particular voices or instruments or for another style of performance
• noun device that enables something to be used in a way different from that for which it was intended or makes different pieces of apparatus compatible