The word "plaguer" means to pester, annoy, or cause trouble. If you're looking for synonyms for the word "plaguer", there are plenty of options. Words such as irritate, bother, vex, harass, or hound can all be used to describe someone who is causing annoyance or trouble. Similarly, the word "nag" can be used to describe someone who is constantly pestering or nagging others. Other synonyms for "plaguer" include troublemaker, agitator, pest, or nuisance. If you're trying to avoid using the word "plaguer" altogether, you may consider using less formal language such as "pain in the neck" or "pain in the rear". Regardless of the specific word or phrase used, it's important to be clear and concise when communicating concerns about someone who is causing annoyance or trouble.