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.

What guards the purity of melting Maids, / In courtly Balls and midnight Maſquerades, / Safe from the treach'rous friend, and daring ſpark, / The glance by day, the whiſper in the dark; / [...] / 'Tis but their Sylph, the wiſe Celeſtials know, / Tho' Honour is the word with Men below.

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.

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.

An assembly of varied, often fanciful, things.

A cosplay event at which costumed attendees perform skits.

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?

There was a Freak took an Aſs in the Head, to Scoure abroad on the Ramble; and away he goes into the Woods, Maſquerading up and down in a Lyon's Skin.

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.

Ethan Hunt, the human missile of American intelligence that Tom Cruise has been popping back in to play for more than 20 years now, is masquerading as a mysterious terrorist, the perfectly named John Lark, to buy back some plutonium he’s lost to a cabal of doomsday extremists.

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