The term "thus termed" can be substituted with various synonyms to add variation to written or spoken language. One alternative could be "hence described," which similarly expresses the idea that something is being defined or labeled a certain way. Another synonym would be "therefore designated," emphasizing the logical connection between the name and the definition. "Termed as such" would also be an acceptable option, noting the traditional use of the term. For those looking for a more informal tone, "called" or "named" can capture the same idea while adding a conversational touch. With a range of choices available, writers and speakers can keep their communication fresh and engaging by swapping out "thus termed" with a synonym that better fits their style.