Pos"sum (?), n. [Shortened from opossum.] Zool.
An opossum.
[Colloq. U. S.]
To play possum, To act possum, to feign ignorance, indifference or inattention, with the intent to deceive; to dissemble; -- in allusion to the habit of the opossum, which feigns death when attacked or alarmed.
© Webster 1913.