Khasa language

Khasa Prakrit (also known as Khas Prakrit, Sanskrit Khasa, Himalayan Prakrit, Northern Prakrit, Khas Kura) is a Prakrit language of medieval South Asia and a common ancestor language of the  Pahari languages, which includes Nepali, Kumaoni, Jaunsari, Mandeali, Kangri and Garhwali languages. It was commonly referred to as खश (Khaśa), खष (Khaṣa), and खशीर ( khaśīra) in the Sanskrit texts.

Indian linguist Suniti Kumar Chatterji suggests that Nepali language developed from Khasa Prakrit. Khas Prakrit is named after the speakers of language, Khas people, who live in the Himalayas.

Origin and development
Khasa belongs to the Indo-European family of languages. Like other Indo-Aryan languages, Khasa is a direct descendant of an early form of Vedic Sanskrit, through Shauraseni Prakrit and Śauraseni Apabhraṃśa (from Sanskrit apabhraṃśa "corrupt").