The address of the residence of the prime minister of the United Kingdom, used by extension to refer to the prime minister or the current UK government. Primarily heard in UK. Swift condemnation of the attack has come from 10 Downing Street, the White House, and the Kremlin.

A fictitious location referring to a place away from possible or looming trouble, taken from the phrase "23 skidoo." Primarily heard in US. Those guys ahead look rough, let's head over to 23 Skidoo Street.

To remain silent; to not say anything; to avoid revealing secret or sensitive information. An alternative spelling of the more common "keep schtum/shtum." It's better to just keep stum when the boss starts flinging accusations than risk further incensing him. We'll need to keep stum about this deal for the time being.