Burushaski (ˌbʊrʊˈʃæski; ) is a language isolate spoken by Burusho people, who reside almost entirely in northern Gilgit-Baltistan, Pakistan, with a few hundred speakers in northern Jammu and Kashmir, India. In Pakistan, Burushaski is spoken by people in Hunza District, Nagar District, northern Gilgit District, the Yasin valley in the Gupis-Yasin District and the Ishkoman valley of the northern Ghizer District. Their native region is located in northern Gilgit–Baltistan and borders with the Pamir corridor to the north. In India, Burushaski is spoken in Botraj Mohalla of the Hari Parbat region in Srinagar. It is generally believed that the language was spoken in a much wider area in the past. Other names for the language are Biltum, Khajuna, Kunjut, Brushaski, Burucaki, Burucaski, Burushaki, Burushki, Brugaski, Brushas, Werchikwar and Miśa:ski.
Attempts have been made to establish links between Burushaski and several different language families, although none has been accepted by a majority of linguists.
Following Berger (1956), the American Heritage dictionaries suggested that the word *abel 'apple', the only name for a fruit (tree) reconstructed for Proto-Indo-European, may have been borrowed from a language ancestral to Burushaski. ("Apple" and "apple tree" are báalt in modern Burushaski.)
Other hypotheses posit a genealogical relationship between Burushaski and the North Caucasian languages, Kartvelian languages, Yeniseian languages and/or Indo-European languages, usually in proposed macrofamilies.
The proposed but contended "Dené–Caucasian" macrofamily includes Burushaski as a primary branch alongside North Caucasian and Yeniseian.
Another proposed family, known as "Karasuk", links Burushaski with Yeniseian.
A relationship to the proposed "Indo-Hittite clade" of the Indo-European family has been suggested by Eric P. Hamp and Ilija Čašule. The various proposals linking Burushaski to Indo-European make divergent—or in the case of Čašule even contradictory—claims about the nature of the relationship, and are rejected by mainstream scholarship.