It's an informal way to say "to put a stop to it" or "to squash it".
Examples:
* "The teacher put the kibosh on talking during the test."
* "My parents put the kibosh on my plans to go to the concert."
* "I tried to get my boss to approve the project, but he put the kibosh on it."
Origin:
The exact origin of "kibosh" is uncertain, but it's believed to have originated in the late 19th century, possibly from the Yiddish word "kibbitz" (meaning to talk or interfere).