- immediately; at once: You'd better get started P.D.Q.
Origin of P.D.Q.
1870–75; p(retty) d(amn) q(uick)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
also pdq, initialism for pretty damn quick, attested from 1875.
Online Etymology Dictionary, © 2010 Douglas Harper