The Collaborative International Dictionary
To play possum
Possum \Pos"sum\, n. [Shortened from opossum.] (Zo["o]l.) 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.
Usage examples of "to play possum".
Submarine captains had devised it as a wartime strategy, in more shallow waters, to play possum in order to evade surface vessels searching for them.
They seemed to have lost a lot of their excitement but they wouldn't be giving up until they'd combed the area in the hope that I'd pulled into a good place to play possum.