To begin with, the word "inimical" means harmful or hostile. Therefore, some synonyms for "make inimical" could include terms such as worsen, deteriorate, or exasperate. Other words that could be used to convey a similar meaning might include phrases such as create animosity, breed hostility, or engender hostility. Overall, the key idea behind "make inimical" is to suggest that a particular action or behavior could have negative consequences, potentially damaging relationships or creating a hostile environment. By using synonyms such as these, writers can convey this idea more effectively while also adding nuance and variety to their vocabulary.