curtain (woven fabric to cover, e.g., windows) / blind (cover for windows) / curtain, veil (something keeping another in secret)

to draw the curtains (closed) / to close down, to close up shop (end)

(theater) final curtain (the last time the curtain is lowered, after a performance and any curtain calls) / (figuratively) final curtain (the end to something that has lasted for a long time)

Iron Curtain

(informal, figuratively) to get one's kicks, to get one's rocks off, to reach seventh heaven (to get a lot of sexual pleasure)

(theater) curtain-raiser

plural of rideau

Alternative spelling of grimper au rideau