Not uniform refers to a situation where things are not consistent or the same. The opposite of not uniform is uniform, which means things are consistent or the same. Other antonyms for not uniform include dissimilar, diverse, varied, different, and heterogeneous. Dissimilar means not alike, diverse means distinctly separate or different, varied means different from one another, and heterogenous means composed of diverse parts or elements. These antonyms are useful to describe situations where things are not consistent or the same, and where differences or variations in appearance, behavior or performance are present. By using antonyms, one can create a more vivid and varied description of a particular situation or object.