The term 'Vain Dudes' can be summarized by the crossword solution of 'FOPS', which is an acronym for 'Foppish or Foppish-like Persons'. FOPS are people who are overly concerned with their appearance and often display a sense of vanity. They are usually men who are preoccupied with their clothing, hairstyle, and other physical attributes. FOPS are often seen as shallow and self-absorbed, and they often lack substance in their conversations.