The Collaborative International Dictionary of English v.0.48:

Slant \Slant\, v. i. [imp. & p. p. Slanted; p. pr. & vb. n.
   Slanting.] [OE. slenten to slope, slide; cf. Sw. slinta to
   slide.]
   To be turned or inclined from a right line or level; to lie
   obliquely; to slope.
   [1913 Webster]

         On the side of younder slanting hill.    --Dodsley.
   [1913 Webster]

WordNet (r) 3.0 (2006):

slanted
    adj 1: having an oblique or slanted direction [syn: aslant,
           aslope, diagonal, slanted, slanting, sloped,
           sloping]
    2: favoring one person or side over another; "a biased account
       of the trial"; "a decision that was partial to the defendant"
       [syn: biased, colored, coloured, one-sided,
       slanted]

Moby Thesaurus II by Grady Ward, 1.0:

44 Moby Thesaurus words for "slanted":
   aslant, aslope, atilt, bevel, beveled, bias, biased, canting,
   careening, cooked, doctored, garbled, inclinational, inclinatory,
   inclined, inclining, leaning, listing, misquoted, misrepresented,
   out of plumb, out of square, perverted, pitched, raking, recumbent,
   shelving, shelvy, sideling, sidelong, slant, slanting, slantways,
   slantwise, sloped, sloping, strained, tilted, tilting, tipped,
   tipping, tipsy, tortured, twisted