What is the meaning of the term "clandestine" in security context?

In the context of security, the term "clandestine" refers to actions or operations that are conducted in secret, often to avoid detection or scrutiny. This aligns closely with the concept of being covert, which implies that something is hidden or not meant to be seen or discovered.

In security practices, clandestine activities may involve covert surveillance, secret communications, or any form of operation where discretion is key to achieving objectives without revealing intentions or details to adversaries. Such operations are often crucial in intelligence and counterintelligence efforts, where maintaining secrecy is vital for effectiveness and safety.

The other options do not embody this meaning; for instance, "obvious" and "transparent" imply a lack of concealment and visibility, while "unauthorized" refers specifically to actions taken without permission, which does not inherently convey the element of secrecy inherent in the term "clandestine."