Sanskrit. The classic language of India (saḿskṛta), the name of which signifies the notion that it is perfectly constructed, being therefore the perfect literary, cultivated language. It is a language of the greatest scholarly importance and is taught in Indian and other universities throughout the world. It is written in the devangārī or "divine" script, developed from an earlier style (Brāhmī) and it reflects a very high degree of sophistication and subtlety of thought.

Geddes MacGregor, Dictionary of Religion and Philosophy, New York: Paragon House, 1989

Sanskrit

The primary language of classical Indian literature, philosophy, and scripture. Its origins are uncertain since the earliest extant inscriptions are rather late. Though it has some links to the language of the vedas, some scholars believe Sanskrit is an artificial language as the name suggests (‘perfected’, ‘completed’) compiled from various dialects and languages current in India during the 4th to 3rd centuries bce. Commanding an enormous prestige and authority, it possesses a complex grammatical structure and a vast vocabulary suited to expressing subtle philosophical and religious concepts. Not used originally by Buddhists, it was adopted first by the Sarvāstivāda school and then later became the standard language for most Mahāyāna literature. A variant form, known to scholars as Buddhist Hybrid Sanskrit, was often used in Mahāyāna sūtras. This is (like Pāli) a form of Middle Indian with a relatively high level of Sanskritization.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)