Source : Webster's Revised Unabridged Dictionary (1913)

Aslope \A*slope"\, adv. & a. [Pref. a- + slope.]
   Slopingly; aslant; declining from an upright direction;
   sloping. ``Set them not upright, but aslope.'' --Bacon.

Source : WordNet®

aslope
     adj : having an oblique or slanted direction [syn: {aslant}, {diagonal},
            {slanted}, {slanting}, {sloped}, {sloping}]