noun

• (figuratively) An act of living under false pretenses; a concealment of something by a false or unreal show; a disguise, a pretence; also, a pretentious display.
  "Verres in the youth of Cicero, Catiline and Clodius in his middle age, Mark Antony in his old age, have all been left to operate on the modern reader's feelings precisely through that masquerade of misrepresentation which invariably accompanied the political eloquence of Rome."
• (figuratively) An assembly of varied, often fanciful, things.
• (fandom slang) A cosplay event at which costumed attendees perform skits.
• (obsolete) A dramatic performance by actors in masks; a mask or masque.

verb

• (intransitive) To take part in a masquerade; to assemble in masks and costumes; (loosely) to wear a disguise.
  "I’m going to masquerade as an old-fashioned pilot. What are you going to dress up as?"
• (intransitive, figuratively) To pass off as a different person or a person with qualities that one does not possess; also, to make a pretentious show of being what one is not.
  "He masqueraded as my friend until the truth finally came out."
• (transitive, rare) To conceal (someone) with, or as if with, a mask; to disguise.