Aerify is defined as the act of adding air to a substance, making it more porous or allowing it to breathe. The antonyms for aerify would be to compress, press, or compact. These terms describe the opposite of aerating, essentially removing air from the substance, making it denser and less breathable. Another antonym for aerify is to suffocate or smother, which means to completely block the flow of air. While aerifying is often done to improve the quality of soil, managing the compactness of soil plays a crucial role in plant growth. Therefore, knowing the antonyms of aerify can help in better understanding and managing air in soil and other materials.