Antonyms for the word "knife-edges" include words such as blunt, dull, rounded, smooth, and flat. Knife-edges can refer to the sharp edges of a knife or any other sharp object, and their antonyms describe the opposite of that sharpness: a lack of sharpness, smoothness, and bluntness. For example, a butter knife has a blunt edge that is not sharp, making it safer to use. Similarly, a rounded edge is curved and not sharp, unlike a knife-edge that is pointed and sharp. A flat edge lacks the sharpness and thinness of a knife-edge, making it less dangerous to handle.