Which adjective best describes an object that is saw-toothed?

The adjective that best describes an object that is saw-toothed is "serrated." This term specifically refers to an edge that has a series of small, sharp notches or teeth along it, resembling the shape of a saw blade. Objects like knives, saws, or certain types of blades often have serrated edges to enhance their cutting ability, allowing them to grip and slice through materials more effectively.

In contrast, the other options present different meanings: "staunch" typically describes something that is firm and steadfast, "staid" refers to being sedate or respectable in character, and "soporific" means inducing sleepiness. None of these descriptors would appropriately convey the specific physical characteristic of having a jagged, toothed edge like that of a saw.