Why is the ninth month called September?
1610s, from Portuguese paria or directly from Tamil paraiyar, plural of paraiyan "drummer" (at festivals, the hereditary duty of members of the largest of the lower castes of southern India), from parai "large festival drum." "Especially numerous at Madras, where its members supplied most of the domestics in European service" [OED]. Applied by Hindus and Europeans to any members of low Hindu castes and even to outcastes. Extended meaning "social outcast" is first attested 1819.
member of a low-caste group of Hindu India, formerly known as "untouchables" but renamed by the Indian social reformer Mahatma Gandhi as Harijans (children of the god Hari Visnu, or, simply, children of God). The word pariah-originally derived from Tamil paraiyar, "drummer"-once referred to the Paraiyan, a Tamil caste group of labourers and village servants of low status, but the meaning was extended to embrace many groups outside the so-called clean caste groups, with widely varying degrees of status. See also untouchable.