Thistle, pigweed, sickelpod, lambs quarters, henbit, curly dock, Johnson grass, perennial ryegrass, Bermuda grass, wild vetch, Virginia creeper, mares tail want me to keep naming them CNC? Heck corn in a soybean field is a weed if it's undesirable. A weed is no specific plant just a plant that's not supposed to be in a specific place. Just so you'll understand.