prototype

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

• noun An original type, form, or instance serving as a basis or standard.
• noun An original, full-scale, and usually working model of a new product or new version of an existing product.
• noun A typical example of a class or category.
• transitive verb To make a prototype of (a product).

from The Century Dictionary.

• noun A primitive form; an original or model after which anything is formed; the pattern of anything to be engraved, cast, etc.; an exemplar; an archetype; especially, in metrology, an original standard, to which others must conform, and which, though it may be imitated from something else, is not required to conform to anything else, but itself serves as the ultimate definition of a unit.

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

• noun An original or model after which anything is copied; the pattern of anything to be engraved, or otherwise copied, cast, or the like; a primary form; exemplar; archetype.

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

• noun An original object or form which is a basis for other objects, forms, or for its models and generalizations
• noun An early sample or model built to test a concept or process
• noun semantics An instance of a category or a concept that combines its most representative attributes.
• noun computing A declaration of a function that specifies the name, return type, and parameters but none of the body, or actual code.
• verb To create a prototype of.

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

• noun a standard or typical example