Specimen, n.
Etymology: [L., fr. specere to look, to behold. See Spy.]
A part, or small portion, of anything, or one of a number of things, intended to exhibit the kind and quality of the whole, or of what is not exhibited; a sample; as, a specimen of a man's handwriting; a specimen of painting; aspecimen of one's art.
Syn. -- Sample; model; pattern. -- Specimen, Sample. A specimen is a representative of the class of things to which it belongs; as, a specimen of photography. A sample is a part of the thing itself, designed to show the quality of the whole; as, a sample of sugar or of broadcloth. A cabinet of minerals consists of specimens; if a part be broken off from any one of these, it is a sample of the mineral to which it belongs. "Several persons have exhibited specimens of this art before multitudes of beholders." Addison. "I design this but for a sample of what I hope more fully to discuss." Woodward.
Shades of meaning
Fernald has no entry of its own for specimen; he lists it under example, sample.
Where he writes about it:
From its original sense of sample or specimen (L. exemplum) example derives the seemingly contradictory meanings, on the one hand of a pattern or model, and on the other hand of a warning--a sample or specimen of what is to be followed, or of what is to be shunned. — from example
An example, however, may be more than a sample or specimen of any class; it may be the very archetype or prototype to which the whole class must conform, as when Christ is spoken of as being an example or leaving an example for his disciples. — from example
A specimen is one unit of a series, or a fragment of a mass, all of which is supposed to possess the same essential qualities; as, a specimen of coinage, or of architecture, or a specimen of quartz. — from sample
No other unit or portion may be exactly like the specimen, while all the rest is supposed to be exactly like the sample. — from sample
An instance is a sample or specimen of action. — from sample