Source : Webster's Revised Unabridged Dictionary (1913)

Parlous \Par"lous\, a. [For perlous, a contr. fr. perilous.]
   1. Attended with peril; dangerous; as, a parlous cough.
      [Archaic] ``A parlous snuffing.'' --Beau. & Fl.

   2. Venturesome; bold; mischievous; keen. [Obs.] ``A parlous
      boy.'' --Shak. ``A parlous wit.'' --Dryden. --
      {Par"lous*ly}, adv. [Obs.] -- {Par"lous*ness}, n. [Obs.]

Source : WordNet®

parlous
     adj : fraught with danger; "dangerous waters"; "a parlous journey
           on stormy seas"; "a perilous voyage across the Atlantic
           in a small boat"; "the precarious life of an undersea
           diver"; "dangerous surgery followed by a touch-and-go
           recovery" [syn: {perilous}, {precarious}, {touch-and-go}]