The phrase "clambers up" refers to the act of climbing or scaling a surface using one's hands and feet. Antonyms for the phrase could include descending, sliding down, or gliding down. These actions involve moving downwards instead of upwards, and may include using different bodily movements to achieve the desired result. Other antonyms for "clambers up" could include walking, running, or simply standing still. Depending on the context of the phrase, various antonyms may be more appropriate. For example, if someone is "clambering up" a ladder, the antonym would likely be "climbing down" or "descending.