Wanakkam, one of the first words a young Tamilien learns: father pushes his son's hands together as the sign of welcome.
Tamil culture is based on the welcome, the hospitality, a due form of respect for others.
A very effective word that I learned many of my foreign friends to say properly : think at 'I want to come' and leave the 'I' out ... it opens the door to the Tamil heart, replied with a smile and wondering eyes !