Vaingloriously is an adverb used to describe someone who acts with excessive pride in their achievements. Some synonyms for the word vaingloriously include arrogantly, pompously, egotistically, conceitedly, narcissistically, and ostentatiously. Other options include haughtily, pretentiously, boastfully, showily, and flamboyantly. These words differ slightly in their connotations, with some implying more overt displays of pride than others. For example, someone who acts ostentatiously might go to great lengths to draw attention to their achievements, while someone who is simply egotistical may just have an inflated sense of self-importance. Regardless of the specific word used, all these synonyms convey a sense of excessive pride and an inflated sense of self-worth.