More than nine-tenths of the population of Madagascar is Malagasy, which is divided into about 20 ethnic groups. The largest and most dominant of the groups is the Merina people, who are scattered throughout the island. The name Merina (Imerina) is said to mean Elevated People, deriving from the fact that they lived on the plateau. The second largest group is the Betsimisaraka (The Inseparable Multitude), who live generally in the east. The third most numerous group is the Betsileo (The Invincible Multitude), who inhabit the plateau around Fianarantsoa. Other important peoples are the Tsimihety (Those Who Do Not Cut Their Hair), the Sakalava (People of the Long Valley), the Antandroy (People of the Thorn Bush), the Tanala (People of the Forest), the Antaimoro (People of the Banks), and the Bara (a name of uncertain origin). Smaller groups are the Antanosy (People of the Island), the Antaifasy (People of the Sand), the Sihanaka (People of the Lake), the Antakarana (People of the Rocks), the Betanimena (People of the Red Soil), who are now largely absorbed by the Merina, the Bezanozano (Those with Many-Braided Hair), and the Mahafaly (Those Who Make Taboos). These ethnic names do not stand for clear-cut cultural boundaries, for in many cases one group shades imperceptibly into another. Moreover, the conventional translations are by no means reliable, and most of the names themselves are of somewhat recent origin, probably crystallized and rigidified by the exigencies of colonial administration more than by the realities of indigenous culture. In many cases, these people represent endogamous and often non-unilinear descent groups.
Encyclopædia Britannica, Inc. Madagascar: Ethnic composition