The antonyms for the phrase "most intermixed" would be "least blended," "separate," "distinct," "diverse," "disparate," "isolated," "segregated," "unalike," "unmixed," "homogeneous," "uniform," or "segregated." These words describe a lack of mixing, unification, or integration between different elements. When things are the least intermixed, they are kept apart, distinct from one another, or completely isolated. In contrast, when things are the most intermixed, they are blended, mixed, or integrated to create a harmonious whole. Understanding the nuances of different antonyms allows us to express ideas with greater precision and clarity.