Other forms: horseradishes
Horseradish is a root vegetable that's closely related to mustard. It's also the name of a sharp-flavored condiment made from the horseradish plant.
You're most likely to find horseradish on a roast beef sandwich or adding its pungent flavor to the cocktail sauce you dip your shrimp in. In Poland and the U.K., horseradish is extremely common, especially as part of a "roast dinner." The prepared horseradish that's used as a condiment is made by grating the plant's root and mixing it with vinegar, salad dressing, or mayonnaise.