One-dimensional refers to something that lacks depth, complexity or nuance. The antonyms for one-dimensional could be multifaceted, multidimensional or diverse. Multifaceted refers to something that has many different aspects or angles, or is capable of performing many different functions. Multidimensional, on the other hand, refers to something that has multiple layers or aspects, or operates in multiple dimensions, such as time or space. Diverse refers to something that is made up of a variety of different elements, or represents a broad range of viewpoints or experiences. By using these antonyms, we can better describe or express things that are more complex, nuanced, and represent a wider range of possibilities.