The phrase "most offending" refers to something that is highly bothersome or offensive. Synonyms for this term include "most repugnant," "most objectionable," "most egregious," "most obnoxious," "most insufferable," and "most intolerable." These words imply a strong sense of disgust or displeasure with the thing being described. Other similar phrases might include "most offensive," "most troublesome," or "most irritating." It's important to choose the right word for the situation to accurately convey your feelings about the object or behavior in question. Whether you're describing a person's behavior or a particular odor, selecting the right synonym can help you express yourself more effectively.