opossum: [17] Opossum comes from aposoum, a word in Virginia Algonquian meaning literally ‘white animal’. The shortened form possum is virtually contemporary with it. When referring to the animal, opossum is now the more usual term, but possum holds its own in the expression play possum ‘feign death or sleep’. Dating from the early 19th century, it alludes to the opossum’s habit of pretending to be dead when threatened. [opossum etymology, opossum origin, 英语词源]