- A grace period of 40 days during which a widow has the right to remain in her dead husband's home, regardless of the inheritance
- A certain place for isolating persons suspected of suffering from a contagious disease.
- A record system kept by port health authorities in order to monitor and prevent the spread of contagious diseases.
- A desert in which Christ fasted for 40 days according to the Bible
- Such official detention of a ship at or off port due to suspicion that it may be carrying a contagious disease aboard.
- (by extension) Any rigorous measure of isolation, regardless of the reason.
- A sanitary measure to prevent the spread of a contagious plague by isolating those believed to be infected.
- A certain period of time during which a person is isolated to determine whether they've been infected with a contagious disease.
- (computing) A place where email messages or other files which are suspected of harboring a virus are stored.
- To put in isolation as if by quarantine
- To retain in obligatory isolation or separation, as a sanitary measure to prevent the spread of contagious disease.