Encroaching upon something implies gradually occupying or invading a space or territory. Some synonyms for "encroaches upon" include infringes upon, treads upon, impinges on, violates, invades, trespassed, and encircles. These words suggest a sense of intrusion or infringement on something that belongs to someone else. For instance, if a company is building a factory in a residential neighborhood, it will encroach upon the serene and peaceful environment of the area. Similarly, the growing population of a city might encroach upon the natural habitats of animals, causing them to migrate or die. The use of synonyms helps us to better understand the nuances of language and communicate more effectively.