A lot vs. Alot: 9 Grammatical Pitfalls
1711, said to be from Malay kichap, but probably not original to Malay. It might have come from Chinese koechiap "brine of fish," which, if authentic, perhaps is from the Chinese community in northern Vietnam [Terrien de Lacouperie, in "Babylonian and Oriental Record," 1889, 1890]. Catsup (earlier catchup, 1680s) is a failed attempt at Englishing, still in use in U.S., influenced by cat and sup.
Originally a fish sauce, the word came to be used in English for a wide variety of spiced gravies and sauces; "Apicius Redivivus; or, the Cook's Oracle," by William Kitchiner, London, 1817, devotes 7 pages to recipes for different types of catsup (his book has 1 spelling of ketchup, 72 of catsup), including walnut, mushroom, oyster, cockle and mussel, tomata, white (vinegar and anchovies figure in it), cucumber, and pudding catsup. Chambers's Encyclopaedia (1870) lists mushroom, walnut, and tomato ketchup as "the three most esteemed kinds." Tomato ketchup emerged c.1800 in U.S. and predominated from early 20c.
seasoned pureed condiment widely used in the United States and Great Britain. American ketchup is a sweet puree of tomatoes, onions, and green peppers flavoured with vinegar and pickling spice that is eaten with meats, especially beef, and frequently with french fried potatoes (British chips); it is the universal condiment of certain fast-food sandwiches. In Britain, as formerly in the United States, ketchup is a puree based on mushrooms, unripe walnuts, or oysters; this ketchup functions primarily as a seasoning for cooking. The word derives from the Chinese ke-tsiap, a fish brine, probably by way of the Malaysian ketjap