Nonabsorbent refers to a material or surface that cannot absorb or soak in any liquid or moisture. The antonyms of nonabsorbent can be classified into two categories, i.e., absorbent and porous. Absorbent means a material that can absorb or soak in liquid or moisture, while porous refers to the quality of a material having small spaces or pores that allow liquid or air to pass through. Some common antonyms for nonabsorbent are absorbent, spongy, porous, permeable, absorptive, and bibulous. For instance, a sponge is absorbent, a paper towel is porous, and a cotton cloth is absorptive. It's essential to use the appropriate antonym based on the material's nature or surface finish to convey the meaning effectively.