class

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A set, collection, group, or configuration containing members regarded as having certain attributes or traits in common; a kind or category.
2. n. A division based on quality, rank, or grade, as:
3. n. A grade of mail: a package sent third class.
4. n. A quality of accommodation on public transport: tourist class.
5. n. A social stratum whose members share certain economic, social, or cultural characteristics: the lower-income classes.
6. n. Social rank or caste, especially high rank.
7. n. Informal Elegance of style, taste, and manner: an actor with class.
8. n. A level of academic development, as in an elementary or secondary school.
9. n. A group of students who are taught together because they have roughly the same level of academic development.
10. n. A group of students or alumni who have the same year of graduation.
11. n. A group of students who meet at a regularly scheduled time to study the same subject.
12. n. The period during which such a group meets: had to stay after class.
13. n. Biology A taxonomic category ranking below a phylum or division and above an order. See Table at taxonomy.
14. n. Statistics An interval in a frequency distribution.
15. n. Linguistics A group of words belonging to the same grammatical category that share a particular set of morphological properties, such as a set of inflections.
16. v. To arrange, group, or rate according to qualities or characteristics; assign to a class; classify.

Century Dictionary and Cyclopedia

1. n. In anc. hist., one of the five divisions of the Roman citizens made, according to their wealth, by Servius Tullius, for purposes of taxation: a sixth division comprised those whose possessions fell below the minimum of the census.
2. n. An order or rank of persons; a number of persons having certain characteristics in common, as equality in rank, intellectual influence, education, property, occupation, habits of life, etc.
3. n. Any body of persons grouped together by particular circumstances or for particular reasons. Specifically— A number of pupils in a school, or of students in a college, of the same grade or pursuing the same studies; especially, in American colleges, the students collectively who are graduated, or in accordance with the rules of the college will be graduated, in the same year. There are four college classes, the freshman or lowest, the sophomore, the junior, and the senior. The word was first used in this sense in American colleges in the Latin form classis, and was borrowed from the universities of continental Europe, where it had during the sixteenth century replaced the medieval lectio.
4. n. A number of objects distinguished by common characters from all others, and regarded as a collective unit or group; a collection capable of a general definition; a kind. A natural class is a set of objects possessing important characters over and above those that are necessary for distinguishing them from others; but the term is applied by naturalists to groups which want this character, and which have not generally retained very long, unchanged, a place in science. See classification.
5. n. In natural history, a group of plants or animals next in rank above the order or superorder, and commonly formed by the union of several orders or superorders: but it may be represented by a single species. See classification. In zoology the class was the highest division of the animal kingdom in the Linnean system, when the word first acquired its technical zoölogical meaning. Linnæus arranged animals in six classes: Mammalia, Aves, Amphibia, Pisces, Insecta, Vermes; the next groups below were the orders. In the Cuvierian system a class was the first division of one of the four “great divisions” of the animal kingdom, Vertebrata, Mollusca, Articulata, and Radiata; thus Cuvier's four classes of Vertebrata were Mammalia, Aves, Reptilia, and Pisces. There are now recognized seven or eight subkingdoms or phyla of animals, divided into about thirty-five classes (see animal kingdom, under animal); the class being the division usually recognized next below the phylum or subkingdom, though some naturalists introduce a superclass, or division between the phylum and the class, as Ichthyopsida for the classes Pisces and Amphibia, or Sauropsida for the classes Aves and Reptilia. The class is always superior to the superorder, order, or suborder, and inferior to the kingdom, subkingdom, or phylum. In botany, likewise, the class is the next principal grade of divisions above the order, and in the Linnean system was the highest grade. The subclass, division, and cohort or alliance are, however, often variously intercalated as subordinate groupings between the class and the order. The phænogamic series or subkingdom of plants includes the three classes of gymnosperms (often united with the next), dicotyledons, and monocotyledons. The cryptogamic series has been ordinarily divided into the two classes of acrogens and thallogens; by recent authorities the number has been increased by three or four or more.
6. n. In geometry, the degree of a locus of planes; a division of algebraical loci bearing an ordinal number showing how many planes there are incident to the locus and passing through each line of Space. In the case of a plane locus, this is the number of lines in the plane incident to the locus and passing through each point in the plane. The ordinal number of the class of an algebraical surface is the number of tangent planes to the surface through each line of space. The class of an algebraical curve of double curvature is the number of osculating planes through each point of space; also, the class of a cone on which the curve lies. The class of an algebraical plane curve is the number of tangents through each point of the plane. The class of a congruence is the number of lines of the congruence passing through each point of space. The class of a complex is the class of the cone of lines of the complex passing through each point of space. The class of a cone is the class of a plane curve lying in it.
7. To arrange in a class or classes; rank together; regard as constituting a class; refer to a class or group; classify; range.
8. To place in ranks or divisions, as students that are pursuing the same studies; form into a class or classes, as in an educational institution. Synonyms Class, Classify; arrange, distribute, dispose. Class is the older and less precise word; it is applied to persons more often than classify. Classify is used in science rather than class, as being more exact.
9. To be arranged or classed.
10. n. In petrography, in the quantitative classification of igneous rocks (see rock), the highest division. All igneous-rock magmas are divided into 5 classes, according to the proportions of salic and femic constituents. The salic minerals are quartz, feldspars, leucite, nephelite, sodalites, corundum, and zircon; the femic minerals are all other minerals except the aluminous ferromagnesian ones. These minerals are calculated from the chemical composition of each rock. The 5 classes are called persalane, dosalane, salfemane, dofemane, and perfemane.
11. n. In shipbuilding, the indication of the character, style of construction, and quality of workmanship and outfit of a merchant vessel, as determined by the rules and inspection of a registration society. The class to which a vessel is assigned is indicated in the register of each society by a conventional character such as 100A, 90A, etc. See A, 2 .
12. n. the indication of the size and power of any given type of war-ship: as, a first-class battle-ship, a first-, second-, or third-class cruiser, etc.
13. n. In crystallog., one of the thirty-two groups in which crystals are divided in accordance with the special type of symmetry which characterizes them. See symmetry.
14. In shipbuilding, to assign to a class of a registration society, such as Lloyd's: said of a merchant vessel. A vessel not classed is one which has not been inspected and assigned a class by any registration society, or the classification of which has been refused for some reason, not necessarily involving deterioration or inferior quality.
15. To be assigned to a class. See I., 3.
16. An abbreviation of classic or classical
17. of classification.

Wiktionary

1. n. countable A group, collection, category or set sharing characteristics or attributes.
2. n. countable A social grouping, based on job, wealth, etc. In Britain, society is commonly split into three main classes; upper class, middle class and working class.
3. n. uncountable The division of society into classes.
4. n. uncountable Admirable behavior; elegance.
5. n. countable and uncountable A group of students in a regularly scheduled meeting with a teacher.
6. n. A series of classes covering a single subject.
7. n. countable A group of students who commenced or completed their education during a particular year. A school class.
8. n. countable A category of seats in an airplane, train or other means of mass transportation.
9. n. biology, taxonomy, countable A rank in the classification of organisms, below phylum and above order; a taxon of that rank.
10. n. Best of its kind.
11. n. mathematics A collection of sets definable by a shared property.
12. n. military A group of people subject to be conscripted in the same military draft, or more narrowly those persons actually conscripted in a particular draft.
13. n. programming A set of objects having the same behavior (but typically differing in state), or a template defining such a set.
14. v. transitive To assign to a class.
15. v. intransitive To be grouped or classed.
16. adj. Ireland, UK, slang great; fabulous

GNU Webster's 1913

1. n. A group of individuals ranked together as possessing common characteristics.
2. n. A number of students in a school or college, of the same standing, or pursuing the same studies.
3. n. A comprehensive division of animate or inanimate objects, grouped together on account of their common characteristics, in any classification in natural science, and subdivided into orders, families, tribes, genera, etc.
4. n. A set; a kind or description, species or variety.
5. n. (Methodist Church) One of the sections into which a church or congregation is divided, and which is under the supervision of a class leader.
6. n. One session of formal instruction in which one or more teachers instruct a group on some subject. The class may be one of a course of classes, or a single special session.
7. n. A high degree of elegance, in dress or behavior; the quality of bearing oneself with dignity, grace, and social adeptness.
8. v. To arrange in classes; to classify or refer to some class.
9. v. To divide into classes, as students; to form into, or place in, a class or classes.
10. v. To be grouped or classed.
11. adj. informal exhibiting refinement and high character. Opposite of low-class

WordNet 3.0

1. n. a body of students who are taught together
2. n. (biology) a taxonomic group containing one or more orders
3. n. people having the same social, economic, or educational status
4. n. elegance in dress or behavior
5. v. arrange or order by classes or categories
6. n. a league ranked by quality
7. n. a collection of things sharing a common attribute
8. n. a body of students who graduate together
9. n. education imparted in a series of lessons or meetings