species

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Biology A fundamental category of taxonomic classification, ranking below a genus or subgenus and consisting of related organisms capable of interbreeding. See Table at taxonomy.
2. n. Biology An organism belonging to such a category, represented in binomial nomenclature by an uncapitalized Latin adjective or noun following a capitalized genus name, as in Ananas comosus, the pineapple, and Equus caballus, the horse.
3. n. Logic A class of individuals or objects grouped by virtue of their common attributes and assigned a common name; a division subordinate to a genus.
4. n. A kind, variety, or type: "No species of performing artist is as self-critical as a dancer” ( Susan Sontag).
5. n. The human race; humankind.
6. n. Roman Catholic Church The outward appearance or form of Eucharistic elements that is retained after their consecration.
7. n. Roman Catholic Church Either of the consecrated elements of the Eucharist.
8. n. Obsolete An outward form or appearance.
9. n. Obsolete Specie.

Century Dictionary and Cyclopedia

1. n. An appearance or representation to the senses or the perceptive faculties; an image presented to the eye or the mind. According to the Roman Catholic doctrine of transubstantiation, the species, the outward and visible forms or the appearance of bread and wine in the eucharist, are the accidents only of bread and wine severally, the substance no longer existing after consecration. See intentional species, below.
2. n. Something to be seen or looked at; a spectacle or exhibition; a show.
3. n. In logic, and hence in ordinary language, a class included under a higher class, or, at least, not considered as including lower classes; a kind; a sort; a number of individuals having common characters peculiar to them.
4. n. One of the kinds of things constituting a combined aggregate or a compound; a distinct constituent part or element; an instrumental means: as, the species of a compound medicine.
5. n. In biology, that which is specialized or differentiated recognizably from anything else of the same genus, family, or order; an individual which differs, or collectively those individuals which differ, specifically from all the other members of the genus, etc., and which do not differ from one another in size. shape, color, and so on, beyond the limits of (actual or assumed) individual variability, as those animals and plants which stand in the direct relation of parent and offspring, and perpetuate certain inherited characters intact or with that little modification which is due to conditions of environment. Species is thus practically, and for purposes of classification, the middle term between genus on the one hand and individual (or specimen) on the other; and only the latter can be said in strictness to have material existence, so that species, like genus, etc., is in this sense an abstract conception. It is also an assured fact in biology that no given stock or lineage breeds perfectly true in all its individuals; the line of descent is always marked by modification of characters (due to the interaction between heredity and environment); the whole tendency of such modification is toward further specialization, in the preservation of the more useful and the extinction of the less useful or the useless characters, and thus to the gradual acquirement, by insensible increments, of differences impressed upon a plastic organism from without—which is as much as to say that new species have always been in process of evolution, and still continue to be so developed. (See biological senses of evolution, selection, survival, and variation.) Such evolution has in fact been arrested at some point for every species once existent whose members have perished in time past; and of those specific forms whose adaptation to their environment has fitted them to survive till the present some are tending to perpetuation and some to extinction, but all are subject to incessant modification, for better or worse. (See atavism, reversion, 2, retrograde, a., 3, degradation, 7, 8, and parasitism, 2.) Such are the views taken by nearly all biologists of the present day, in direct opposition to the former opinion of a special creation, which proceeded upon the assumption that all species of animals and plants, such as we find them actually to be, came into existence by creative flat at some one time, and have since been perpetuated with little if any modification. In consequence of the fact that the greatest as well as the least differences in organisms are of degree and not of kind, no rigorous and unexceptionable definition of species is possible in either the animal or the vegetable kingdom; and in the actual naming, characterizing, and classifying of species naturalists differ widely, some reducing to one or two species the same series of individuals which others describe as a dozen or twenty species. (See lumper, 3, splitter, 2.) This, however, is rather a nomenclatural than a doctrinal difference. The difficulty of deciding in many cases, and the impossibility of deciding in some, what degree of difference between given specimens shall be considered specific, and so formally named in the binomial system, have led to the introduction of several terms above and below the species (see subgenus, subspecies, conspecies, variety, race, 5 , intergrade, v. i.), and also to a modification of the binomial nomenclature (see polynomial, 2, and trinomial). Two tests are commonly applied to the discrimination between good species and mere subspecies or varieties:
6. n. Coin; metallic money; specie. See specie.
7. n. One of a class of pharmaceutical preparations consisting of a mixture of dried herbs of analogous medicinal properties, used for making decoctions, infusions, etc. See under tea.
8. n. In civil law, the form or shape given to materials; fashion; form; figure.
9. n. In mathematics: A letter in algebra denoting a quantity. [This meaning was borrowed by some early writers from the French of Viète, who derived it from a Latin translation of Diophantus, who uses ει%27δος to mean a term of a polynomial in a particular power of the unknown quantity.]
10. n. A fundamental operation of arithmetic. See the four species, below.
11. n. A former standard of currency in certain parts of Germany and in the north of Europe, apparently answering to the modern dollar of commerce.

Wiktionary

1. n. A type or kind of thing.
2. n. A group of plants or animals having similar appearance.
3. n. biology, taxonomy A rank in the classification of organisms, below genus and above subspecies; a taxon at that rank
4. n. mineralogy A mineral with a unique chemical formula whose crystals belong to a unique crystallographic system.
5. n. obsolete The image of something cast on a surface, or reflected from a surface, or refracted through a lens or telescope; a reflection.
6. n. Roman Catholicism Either of the two elements of the Eucharist after they have been consecrated, so named because they retain the image of the bread and wine before their transubstantiation into the body and blood of Christ.

GNU Webster's 1913

1. n. rare Visible or sensible presentation; appearance; a sensible percept received by the imagination; an image.
2. n. (Logic) A group of individuals agreeing in common attributes, and designated by a common name; a conception subordinated to another conception, called a genus, or generic conception, from which it differs in containing or comprehending more attributes, and extending to fewer individuals. Thus, man is a species, under animal as a genus; and man, in its turn, may be regarded as a genus with respect to European, American, or the like, as species.
3. n. In science, a more or less permanent group of existing things or beings, associated according to attributes, or properties determined by scientific observation.
4. n. A sort; a kind; a variety
5. n. obsolete Coin, or coined silver, gold, or other metal, used as a circulating medium; specie.
6. n. obsolete A public spectacle or exhibition.
7. n. A component part of a compound medicine; a simple.
8. n. (Med.) An officinal mixture or compound powder of any kind; esp., one used for making an aromatic tea or tisane; a tea mixture.
9. n. (Civil Law) The form or shape given to materials; fashion or shape; form; figure.

WordNet 3.0

1. n. (biology) taxonomic group whose members can interbreed
2. n. a specific kind of something