Charades is a game of acting a title out without speaking. Play charades, a game of charades, win at charades.
The conventions are fixed and taught by playing — sounds like, first syllable, a whole word — and they work in every language that plays it. As an insult a charade is a pretence everybody can see through, which is a different word made singular.
1nouncharadesA game of acting a title out without speaking.
“At Christmas, our family always plays charades after dinner.”
charades is a game.
French charade named a riddle. The game was first called acting charades or dumb charades, and the noun settled as a plural.
See charade. As a game, originally a clipped form of acting charades or, without talking, dumb charades but now usually understood as a plurale tantum.
Etymology from Wiktionary, CC BY-SA