Heterology is a term that refers to the study of dissimilar or incongruent systems. It is often used in medical research and other scientific fields to describe the differences between related biological systems. However, if you are looking for synonyms to expand your vocabulary, you could use words such as heterogeneity, dissimilarity, diversity, variation, discrepancy, or nonconformity. These words present a range of shades of meaning, but all indicate some form of difference. Using synonyms gives you the ability to communicate more effectively and avoid repetition in your writing. It is essential to have a robust vocabulary set to express yourself with more clarity and precision.