1
general::
Make a speedy departure, run away, as in I looked around and he was gone? he'd taken a powder. This slangy idiom may be derived from the British dialect sense of powder as "a sudden hurry," a usage dating from about 1600. It may Also allude to the explosive quality of gunpowder.
American Heritage Idioms
2
general::
Phrase(s): take a powder
Sl. to leave; to leave town. (Underworld.) • Why don’t you take a powder? Go on! Beat it! • Willie took a powder and will lie low for a while.
McGrawhill's American Idioms And Phrasal Verbs