Merriam-Webster's Collegiate® Dictionary, 11th Edition
QUARANTINE
I. noun see: four
Date: 1609
a period of 40 days,
2. a term during which a ship arriving in port and suspected of carrying contagious disease is held in isolation from the shore, a regulation placing a ship in quarantine, a place where a ship is detained during quarantine,
3. a restraint upon the activities or communication of persons or the transport of goods designed to prevent the spread of disease or pests, a place in which those under quarantine are kept, a state of enforced isolation,
II. verb (-tined; -tining)
Date: 1804
transitive verb to detain in or exclude by quarantine, to isolate from normal relations or communication , intransitive verb to establish or declare a quarantine