Self-importantly is a word that describes an individual who behaves in a conceited, pompous or egotistical manner. It can be replaced with various other words that convey similar sentiments. Arrogantly, haughtily, pretentiously, pompously, immodestly, egocentrically, narcissistically, and condescendingly are all synonyms for self-importantly. These words describe people who believe they are superior in some manner, without valid reason or purpose. In any context, these words can help to add nuance and precision to one's writing or speech, ensuring that the message is better conveyed and understood. Therefore, it is important to use them as appropriate in the right context for better expression and clarity of communication.