Conducted with secrecy; withdrawn from public notice, usually for an evil purpose; kept secret; hidden; private; underhand; as, a clandestine marriage.

Something kept purposely from the view or knowledge of others either in violation of the law or to conduct or conceal some illegal purpose. A "clandestine marriage" would be one which does not comply with laws related to publicity.

Means: secret. When bosses should not know who is resisting against their measures, reducing the work rhythm or deciding to push through longer breaks, then it has to be organised in a clandestine way.

conducted with or marked by hidden aims or methods; "clandestine intelligence operations"; "cloak-and-dagger activities behind enemy lines"; "hole-and-corner intrigue"; "secret missions"; "a secret agent"; "secret sales of arms"; "surreptitious mobilization of troops"; "an undercover investigation"; "underground resistance"

Concealed, usually for some secret or illicit purpose. In Freemasonry, illegal, not authorized.

Clandestine is an album by Scandinavian death metal band Entombed, released in 1991. It helped establish a distinctively Swedish sound in the death metal genre, while being more accessible than its predecessor, the atonal debut Left Hand Path. Largely written by drummer Nicke Andersson, the album's slowed-down speed metal rhythms have remained perhaps its most notable hallmark.