Prototype

Webster's Dictionary definitions:

1) An original model on which something is patterned.

2) An individual that exhibits the essential features of a later type.

3) A standard or typical example.

4) A first full-scale and usually functional form of a new type or design of a construction (as an airplane).

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Dictionary.com's definitions [1 exception]:

1) An original type, form, or instance serving as a basis or standard for later stages.

2) An original, full-scale, and usually working model of a new product or new version of an existing product.

3) An early, typical example.

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Oxford's Dictionary definitions:

1) A first or preliminary form from which other forms are developed or copied.

2) A typical example of something.

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Encarta.com Dictionary definitions [1 exception]:

1) Original used as model: something having the essential features of a subsequent type, and on which later forms are modeled.

2) Standard example: a standard example of a particular kind, class, or group.

3) Full-size functional model: a first full-size functional model to be manufactured, for example, of a car or a machine.