What is Classical?

Classical definition and meaning on Dictionary terms:
of, relating to, or characteristic of Greek and Roman antiquity: classical literature; classical languages.
conforming to ancient Greek and Roman models in literature or art, or to later systems modeled upon them.
marked by classicism: classical simplicity.
Music. of, relating to, or constituting the formally and artistically more sophisticated and enduring types of music, as distinguished from popular and folk music and jazz. Classical music includes symphonies, operas, sonatas, song cycles, and lieder. of, pertaining to, characterized by, or adhering to the well-ordered, chiefly homophonic musical style of the latter half of the 18th and the early 19th centuries: Haydn and Mozart are classical composers.

Architecture. noting or pertaining to the architecture of ancient Greece and Rome, especially the religious and public architecture, characterized by the employment of orders.Compare order(def 27b). noting or pertaining to any of several styles of architecture closely imitating the architecture of ancient Greece or Rome; neoclassic. noting or pertaining to architectural details or motifs adapted from ancient Greek or Roman models. (of an architectural design) simple, reposeful, well-proportioned, or symmetrical in a manner suggesting the architecture of ancient Greece and Rome.

(often initial capital letter) pertaining to or designating the style of fine arts, especially painting and sculpture, developed in Greece during the 5th and 4th centuries b.c., chiefly characterized by balanced composition, the separation of figures from an architectural background, and the naturalistic rendering of anatomical details, spatial movement, and distribution of weight in a figure.Compare archaic(def 4), Hellenistic(def 5).
of or relating to a style of literature and art characterized by conformity to established treatments, taste, or critical standards, and by attention to form with the general effect of regularity, simplicity, balance, proportion, and controlled emotion (contrasted with romantic).
pertaining to or versed in the ancient classics: a classical scholar.
relating to or teaching academic branches of knowledge, as the humanities, general sciences, etc., as distinguished from technical subjects.
(of a given field of knowledge) accepted as standard and authoritative, as distinguished from novel or experimental: classical physics.
classic(defs 1