classical

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

• adjective Of or relating to the ancient Greeks and Romans, especially their art, architecture, and literature.
• adjective Conforming to the artistic and literary models of ancient Greece and Rome.
• adjective Versed in the classics.
• adjective Of or relating to European music during the latter half of the 18th and the early 19th centuries.
• adjective Of or relating to music in the educated European tradition, such as symphony and opera, as opposed to popular or folk music.
• adjective Of, relating to, or being a variety of a language that is epitomized by a prestigious body of literature.
• adjective Standard and traditional.
• adjective Relating to or being a school of thought or field of study that is established and widely accepted before others.
• adjective Of or relating to physics that can be described without the use of quantum mechanics or relativity.
• adjective Relating to or consisting of studies in the humanities and general sciences.

from The Century Dictionary.

• Belonging to or associated with the first or highest class in literature, especially in literary style.
• Pertaining to writers of the first rank among the moderns; constituting the best model or authority as a composition or an author.
• Hence In general, of the first rank, or constituting a model, in its kind; having in a high degree the qualities which constitute excellence in its kind: as, a classical work of art.
• Same as classic, 2 and 3.
• Pertaining to a class; of the taxonomic rank or grade of a class.
• Belonging to classification; classificatory.
• In some Reformed churches, relating to or of the nature of a classis or class. See classis, 2.
• Belonging or pertaining to a fleet.
• In music, belonging or pertaining to a style of composition in which regularity of form is conspicuous, particularly to the style developed in the latter part of the eighteenth century: opposed to romantic. Thus Haydn's music is classical, while Schumann's is mostly romantic. The term is also loosely used of all music that is elaborate, difficult, or abstruse: opposed to popular.

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

• adjective Of or relating to the first class or rank, especially in literature or art.
• adjective Of or pertaining to established principles in a discipline.
• adjective music Describing European music and musicians of the late 18th and early 19th centuries.
• adjective informal, music Describing serious music (rather than pop, jazz, blues etc), especially when played using instruments of the orchestra.
• adjective Of or pertaining to the ancient Greeks and Romans, especially to Greek or Roman authors of the highest rank, or of the period when their best literature was produced; of or pertaining to places inhabited by the ancient Greeks and Romans, or rendered famous by their deeds.
• adjective Conforming to the best authority in literature and art; chaste; pure; refined; as, a classical style.

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

• adjective of recognized authority or excellence
• adjective of or relating to the most highly developed stage of an earlier civilisation and its culture
• adjective of or relating to the study of the literary works of ancient Greece and Rome
• noun traditional genre of music conforming to an established form and appealing to critical interest and developed musical taste
• adjective (language) having the form used by ancient standard authors
• adjective of or pertaining to or characteristic of the ancient Greek and Roman cultures