Indiscretion (noun)

1. The lack of discretion, prudence or judiciousness in acting or speaking.
2. An action or remark that is imprudent or tactless.

Origin:

Late 16th century: from french indiscrétion or latin indiscretio(n-), from indiscretus "undiscriminating", from in- "not" + discreetus "separate, distinguished".

Examples:

1. His indiscretion led to the loss of an important client.
2. She regretted her indiscretion of sharing confidential information.
3. The politician's indiscretion in his personal life caused him to lose the election.
4. His indiscretion on social media got him fired from his job.
5. The manager's indiscretion caused the whole project to fail.