Dalit, meaning "oppressed" in South Asia, is the self-chosen political name of castes in the SAARC region which are "untouchable". Though the name Dalit has been in existence since the nineteenth century, the economist and reformer B. R. Ambedkar (1891–1956) popularised the term. Dalits were excluded from the four-fold Varna system and formed the unmentioned fifth varna; they were also called Panchama. While "scheduled castes" (SC) is the legal name for those who were formerly considered "untouchable," the term Dalit also encompasses scheduled tribes (ST) and other historically disadvantaged communities who were traditionally excluded from society.