MASQUERADE

An assembly or party of people wearing (usually elaborate or fanciful) masks and costumes, and amusing themselves with dancing, conversation, or other diversions.

"I was invited to the masquerade party at their home."

The act of wearing a mask or dressing up in a costume for, or as if for, a masquerade ball.

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.

To take part in a masquerade; to assemble in masks and costumes; to wear a disguise.

"I’m going to masquerade as the wikipede. What are you going to dress up as?"

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."

To conceal (someone) with, or as if with, a mask; to disguise.