exemplar

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

• noun One that is worthy of imitation; a perfect example or model. synonym: ideal.
• noun One that is typical or representative; an example.
• noun A copy, as of a book.

from The Century Dictionary.

• Serving as an example; exemplary.
• Conveying a warning; fitted to warn or deter.
• Pertaining or relating to an example or to examples; containing or constituting an example.
• noun A model, original, or pattern to be copied or imitated; the idea or image of a thing formed in the mind; an archetype.
• noun A specimen; a copy, especially a copy of a book or writing.

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

• noun A model, original, or pattern, to be copied or imitated; a specimen; sometimes; an ideal model or type, as that which an artist conceives.
• noun obsolete A copy of a book or writing.
• adjective obsolete Exemplary.

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

• noun Something fit to be imitated; see ideal and model.
• noun Something typical or representative of a class; see example.
• noun A pattern after which others should be made; see archetype.
• noun A well known usage of a scientific theory.
• noun A handwritten manuscript used by a scribe to make a handwritten copy; the original copy of what gets multiply reproduced in a copy machine.
• adjective obsolete Exemplary.

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

• noun something to be imitated