The antonyms for "more asperous" can be smooth, even, polished or sleek. Smooth refers to the absence of any roughness or unevenness, whereas even denotes a surface that is level and uniform in texture. Polished implies a surface that is refined and shiny, and sleek is used to describe a surface that is smooth and slippery to the touch. All these antonyms collectively describe a surface that is opposite to asperous which means rough, irregular or bumpy. The choice of an antonym for asperous depends on the context, and it's important to use the appropriate term that accurately reflects the intended meaning.