transformer

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

• noun One that transforms.
• noun A device used to transfer electric energy from one circuit to another, especially a pair of multiply wound, inductively coupled wire coils that effect such a transfer with a change in voltage, current, phase, or other electric characteristic.

from The Century Dictionary.

• noun A transformer designed for use in multiple with other transformers on the same circuit.
• noun A name sometimes given to the dynamostatic machine of Elihu Thomson.
• noun One who or that which transforms.

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

• noun One who, or that which, transforms. Specif. (Elec.), an apparatus for producing from a given electrical current another current of different voltage.
• noun a toy consisting of a figure or representation of an object, constructed of interlocking parts in such a way that a series of turning or twisting motions of the parts can transform the object from one type of object to a different type of object, such as from an animal to an automobile.
• noun (Elec.) A transformer with more than one primary or more than one secondary coil.
• noun (Elec.) a transformer connected in parallel.

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

• noun Something that transforms, changing its own or another thing's shape.
• noun electrical engineering A static device that transfers electric energy from one circuit to another by magnetic coupling. Their main use is to transfer energy between different voltage levels, which allows choosing most appropriate voltage for power generation, transmission and distribution separately.

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

• noun an electrical device by which alternating current of one voltage is changed to another voltage