The phrase "put/get someones back up" means to cause someone to become angry, irritated, or defensive. It is an idiomatic expression that is commonly used in informal settings. Some synonyms for this phrase include "irritate," "bother," "annoy," "frustrate," "provoke," and "anger." Each of these synonyms convey the same idea that someone is causing another person to become upset or defensive. It is important to use synonyms like these to add variety to your language and to avoid repeating the same phrases over and over again. By using synonyms, you can make your writing more interesting and engaging for your reader.