[Meaning] to accomplish something knavishly.[1] "The business [is] clever and very much in your style; for the prize-cake of [= for] contrivance [is] ours." The puramou=s [is] a kind of flat-cake; this used to be set as a prize for those keeping an all-nighter, and he who was awake until dawn used to receive it as victor. So figuratively [Aristophanes] used it as of his [Euripides'] surpassing everyone in rascality.