Boastfulness refers to the act of excessively bragging or boasting about one's achievements or qualities. There are several synonyms for this word, including conceit, vanity, egotism, arrogance, and hubris. Conceit refers to an excessively high opinion of oneself and one's abilities, while vanity refers to an excessive focus on one's appearance or social status. Egotism involves an obsession with oneself and a disregard for others' feelings, while arrogance indicates a belief that one is superior to others. Hubris is an overbearing pride that leads to recklessness or downfall. All of these words describe a negative trait that can repel others and hinder personal and professional growth.