What term is defined as a resemblance in specific aspects between otherwise unlike things?

The correct term that describes a resemblance in specific aspects between otherwise unlike things is "analogy." An analogy draws a parallel between two different entities by highlighting their similarities in particular characteristics or functions, often to clarify or explain a concept. For instance, when likening the structure of an atom to a solar system, one uses an analogy to make the concept of atomic structure more relatable.

While other terms may seem similar, they serve different purposes. A metaphor directly states that one thing is another, enriching meaning but not necessarily focusing on the comparative aspects that an analogy does. A simile, on the other hand, uses "like" or "as" to compare two things, providing a more straightforward and specific comparison. Symbolism involves representing an idea or concept through symbols, which is more abstract and does not explicitly emphasize resemblance. Thus, "analogy" is the most fitting choice for describing a resemblance in specific aspects between dissimilar entities.