Pŏs'sum, n.

noun

n. [Corrupted from opossum.] The opossum. [Colloq. U. S.]

To play possum, to act possum, to feign inactivity, indifference, or inattention, with the intent to deceive;—so applied in allusion to the habit of the opossum, which feigns death when attacked or alarmed.