The phrase "bug up" can have a variety of meanings, from "annoy" to "bother" to "frustrate." If you find yourself using this phrase frequently, it may be beneficial to expand your vocabulary with some synonyms. Here are a few options: "irritate," "agitate," "perturb," "vex," "exasperate," "provoke," "nettle," "ruffle," or "irk." By incorporating these words into your language, you can better convey your thoughts and feelings in a more nuanced and specific manner. Remember, there are always alternatives to commonly used phrases - keep your vocabulary engaging and exciting!