When we talk about the opposite of "most slipping," one of the antonyms that comes to mind is "stable." Unlike something that is most slipping, a stable object or situation refers to something that is motionless, firm, and secure. Additionally, "gripping" or "tenacious" can be useful antonyms as they refer to something that is tightly held or firm. Another antonym could be "reliable," which denotes something that can be counted on without fail. Lastly, "steady" can also be considered an antonym, as it implies a situation that is constant or consistent over time, unlike something that is most slipping, which is prone to sudden and dramatic changes.