Borean (also Boreal or Boralean) is a hypothetical linguistic macrofamily that encompasses almost all language families worldwide except those native to the Americas, Africa, Oceania, and the Andaman Islands. Its supporters propose that the various languages spoken in Eurasia and adjacent regions have a genealogical relationship, and ultimately descend from languages spoken during the Upper Paleolithic in the millennia following the Last Glacial Maximum. The name Borean is based on the Greek βορέας, and means "northern". This reflects the fact that the group is held to include most language families native to the northern hemisphere. Two distinct models of Borean exist: that of Harold C. Fleming and that of Sergei Starostin.
The concept is due to Harold C. Fleming (1987), who proposed such a "mega-super-phylum" for the languages of Eurasia, termed Borean or Boreal in Fleming (1991) and later publications. In Fleming's model, Borean includes ten different groups: Afrasian (his term for Afroasiatic), Kartvelian, Dravidian, a group comprising Sumerian, Elamitic, and some other extinct languages of the ancient Near East, Eurasiatic (a proposal of Joseph Greenberg that includes Indo-European, Uralic, Altaic, and several other language families), Macro-Caucasian (a proposal of John Bengtson that includes Basque and Burushaski), Yeniseian, Sino-Tibetan, Na-Dene, and Amerind.
Harold C. Fleming, in 2002, argued that there were not a two large super-phyla distinction between a Nostratic and a Dené–Caucasian taxon among Borean languages, and that the language kinship between its branches is possibly more complex than a Nostratic versus a Dené–Caucasian super-phyla.
However, in 2013, Harold C. Fleming had changed his view about this issue in a joint article with Stephen L. Zegura, James B. Harrod, John D. Bengtson and Shomarka O.Y. Keita - "The Early Dispersions of Homo Sapiens sapiens and proto-Human from Africa." in Mother Tongue, issue XVIII, p. 143-188, 2013, where he argues that Nostratic and Dene-Caucasian as language phyla within Borean is a hypothesis that is well grounded and convincing.