quarantine [LME] Literally meaning ‘40 days’, quarantine comes from Italian quarantina, from quaranta ‘40’. In the early 16th century this was the number of days during which a widow had the right to remain in her deceased husband’s house. A more familiar meaning refers to a period of isolation imposed on a person or animal to test that they are not carrying a contagious disease. This was first used in English in the mid 17th century, though the practice dates back to the 14th century, when the ports of Venice and Ragusa (now Dubrovnik) required ships from plague-stricken countries to lie at anchor for 40 days before they were allowed to enter the ports.