The term curry is derived from kari pronounced (ka-di), (a Tamil word meaning sauce and referring to various kinds of dishes common in South India made with Vegetables or Meat and usually eaten with rice. However, the term (meaning a stew) is found in the English dictionary and after the arrival of British traders on the Subcontinent, may simply have been applied by them, to dishes which they thought resembled the stews they were used to. Nowadays the term is used more broadly, especially in the West, to refer to almost any spiced, sauce-based dish cooked in various South East Asian styles.
This imprecise blanket term is largely a creation of the British Empire or the British Raj as it has more popularly been referred to. Curry was originally used to mask the taste of bad meat. Not all curries are made from curry powder; in fact, in India, the word curry is seldom used. Instead, most dishes involving lentils are called daal, or else are referred to by a name specific to the spices used in the preparation example Murg Adraki (Ginger Chicken) or Jeera Murg(Cumin Chicken) . Meat or Vegetable dishes are likewise given specific names that indicate the method of cooking, or the particular spices used.
http://en.wikipedia.org/wiki/Curry
http://en.wikipedia.org/wiki/Curry_powder
http://indianfood.about.com/od/frequentlyaskedquestions/f/curryfaq.htm
http://dinnercoop.cs.cmu.edu/dinnercoop/Recipes/karen/CurryPowder.html
http://acecurriestogo.com/
http://www.slate.com/articles/life/food/2013/01/indus_civilization_food_how_scientists_are_figuring_out_what_curry_was_like.html