Take a powder

[Rudolph C Troike]

Just to highlight this sub-thread, I wanted to mention that my early and
enduring impression of the context for this expression was that it was
mobster-slang from the 1920s (Al Capone, et al.). This suggests that its
origins were far from referring delicately to ladies repairing to the
restroom. The implication seemed to be to leave the scene precipitously
(and surreptitiously) to avoid being captured or rubbed out, and unlikely
to return soon. These are purely impressionistic interpretations, however.

        Rudy