Zeitun is a Middle-Eastern term for Olives. In hindi it is called Jaitun and the same in Gujarati. (look here for the info)
It didn't originated from one language but perhaps a mix of different languages.
The olive is the only member of the Oleaceae to bear edible fruit. The fruit, a drupe like a peach, cannot be eaten fresh because of the presence of a bitter glucoside. Thus the olive must be processed in order to be served as food; either processed for its oil or processed with lye and salt to produce the canned or preserved table fruit. While fruit processed in California has almost all of the bitterness removed, that processed in the Mediterranean area is often left somewhat bitter.
Tapenade is a Provençal dish consisting of pureed or finely chopped olives, capers, and olive oil. Its name comes from the Provençal word for capers, tapéno. It is a popular food in the south of France, where it is generally eaten as an hors d’œuvre, spread on gourmet breads such as baguette or ciabatta. Sometimes it is also used to stuff fillets for a main course.
The recipe: Makes about 1/2 cup
1 cup of mixed olives, black and green
1 garlic cloves, sliced
1 tbsp minced fresh parsley
1 tbsp salted capers, rinsed and dried (optional)
2 tsp lemon zest (optional)
Freshly ground black pepper, to taste
2 to 3 tbsp extra virgin olive oil
lemon juice to taste
Put olives, parsley, garlic, capers, lemon zest and process it by drizzling olive oil from the feeding tube. Once its finely minced. Take it out in a bowl and adjust the seasonings.
Set aside for 30 minutes before serving. Serve it on a toasted sliced baguette (crostini) or eat with crackers or toasted pita bread. It's tastes so good.
The tapenade will keep in the refrigerator for a day or two, after that its flavors will deteriorate. You can make this tapenade using almost any olive, including the mixed olives sold at the olive bars common in upscale markets these days.
If you select the olives yourself, try a mix of kalamatas, picholines, cracked green, and California black.
Salted capers are available in good delis and markets.
P.S: Do not add salt as olives are very salty and if using capers they have lot of salt too.