Here is a picture of a parai. As you can tell, dear reader, a parai is a drum. Specifically, it is an ancient Tamil drum.
Like eggs, carpets, and the England football team, it is in the nature of a drum that it should be beaten. In the festivals of Kerala and of Tamil Nadu such drums are beaten by members of a particular tribe and so that tribe was named the Paraiyar.
The poor Paraiyar were considered to be unclean. The first mention of them in English comes from Samuel Purchas' Pilgrimes (1613) and reads:
The Pareas are of worse esteem.... reputed worse than the Divell.
In fact, the Paraiyar were considered to be beneath everybody except the washermen and the shoemakers (who were a load of cobblers*). So put upon and oppressed were the Paraiyar that, among the European invaders of India, they became a byword for outcasts. The Portuguese spelt the name Paria, and we, being British and fond of unnecessary 'H's called them Pariahs. Hence the word.
English has now acquired the phrase pariah state which is thrown hither and thither like a befaeced tennis ball. But in fact, no Pariah state exists. The Paraiyar are alive and well, but have neither independence nor autonomy.
There was, though, a Pariah Poet. His name was Tiruvalluvar and he once wrote:
Call him not 'man' who makes display of useless words:
Call him but 'chaff of humankind.'
The fool's intrusion in th'assembly of the wise
Is like one placing dirty feet upon a lovely couch.
I'm not sure that Tiruvallar and I would get along.
Well, I'd never do a thing like that.
*Cockney rhyming slang: cobblers' awls = balls.