A more thorough explanation:

Definition: Secret or concealed, especially for illegal or unauthorized purposes.

Examples:

• A group of teenagers planned a clandestine party in an abandoned warehouse.
• The spy carried out clandestine operations in foreign countries.
• The company's clandestine activities were exposed by a whistleblower.

The examples illustrate the definition of clandestine by showing situations where something is kept secret or concealed for illegal or unauthorized purposes. In the first example, the teenagers plan a party in an abandoned warehouse without permission, which is illegal. In the second example, the spy carries out secret operations in foreign countries, which is unauthorized. In the third example, the company engages in secret activities that are not allowed by law.