ketchup
Synonym discussion
Sense: noun/1
Ketchup, tomato sauce, and catsup are all tomato-based condiments, but they differ in use and texture. Ketchup is always served cold and has a smooth, thick consistency with a sweet-and-sour vinegar taste; it is typically squeezed or poured onto burgers, hot dogs, and fries. Tomato sauce is a broader term — it can mean ketchup in British English, but in cooking contexts it refers to a cooked, often chunky sauce for pasta or pizza. Catsup is simply an older spelling of ketchup that appears on a few American brands but is otherwise identical. Relish is chunkier and made from chopped vegetables or fruit rather than puréed tomatoes. Condiment is the general category word for any seasoning added to food at the table (ketchup, mustard, relish, hot sauce, etc.). For example, you might ask for 'ketchup and mustard' for a hot dog, but you would order 'pasta with tomato sauce', not 'pasta with ketchup'.
Common collocations
Etymology
The word ketchup comes from the Chinese word kê-tsiap (a pickled fish sauce), which was brought to Southeast Asia by traders and later reached England. Early English versions used mushrooms, walnuts, or oysters instead of fish. The modern tomato-based recipe became popular in the United States in the 1800s, and the spelling 'ketchup' became the standard form.