The word "stresser" refers to something or someone that causes stress. There are several synonyms for this word, including stressor, pressure point, strain inducer, tension creator, worrier, aggravator, and irritant. These words can be used interchangeably in a sentence, depending on the context and the level of stress being experienced. For instance, a difficult task at work could be called a stressor or pressure point. Likewise, someone who is constantly nagging or causing problems could be called an irritant or aggravator. Overall, these synonyms help to describe the various factors that contribute to stress in our daily lives.