Vain is a word that often refers to someone who is excessively obsessed with themselves, their appearance, or their accomplishments. Some synonyms for vain include conceited, narcissistic, egotistical, self-centered, and self-absorbed. Other possible synonyms are arrogant, haughty, proud and snobbish. These words imply a lack of humility and a tendency to prioritize oneself over others. Vain may also be similar to words like superficial, shallow, and materialistic, which suggest a focus on outward appearances rather than substance. However, it is important to note that some words may have nuances in meaning that make them more appropriate in certain contexts than others.