(physics) All of the physical laws of nature that account for the behaviour of the normal world, but break down when dealing with the very small (see quantum mechanics) or the very fast or very heavy (see relativity).

(music) Music of the classical period; the music of Mozart, Haydn, etc; the musical period before the romantic.

The form of Ancient Greek language used during the classical period of Greek literature: approximately 600 to 300 BCE.

(psychology) A learning process in which a previously neutral stimulus (such as a bell) is paired with a potent stimulus (such as food in the case of a dog), so that the neutral stimulus comes to elicit a conditioned response (salivation) similar to the one elicited by the potent stimulus.

(baseball) The World Series.

A codified form of Sanskrit spoken in ancient India.

(physics) all aspects of physics developed before the rise of quantum mechanics

The variants of the Nahuatl language spoken in central Mexico at the time of the Spanish conquest.

Any of several periods of history noted for a particular style of art, architecture, literature or music termed classical

The form of Tibetan spoken from the early 10th century AD until the 12th century AD (after the Old Tibetan period) and still used as a written language.