The Collaborative International Dictionary of English v.0.48:

Askance \A*skance"\, Askant \A*skant"\, adv. [Cf. D. schuin,
   schuins, sideways, schuiven to shove, schuinte slope. Cf.
   Asquint.]
   Sideways; obliquely; with a side glance; with disdain, envy,
   or suspicion.
   [1913 Webster]

         They dart away; they wheel askance.      --Beattie.
   [1913 Webster]

         My palfrey eyed them askance.            --Landor.
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         Both . . . were viewed askance by authority.
                                                  --Gladstone.
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The Collaborative International Dictionary of English v.0.48:

Askance \A*skance"\, v. t.
   To turn aside. [Poet.]
   [1913 Webster]

         O, how are they wrapped in with infamies
         That from their own misdeeds askance their eyes!
                                                  --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

askance
    adv 1: with suspicion or disapproval; "he looked askance at the
           offer"
    2: with a side or oblique glance; "did not quite turn all the
       way back but looked askance at me with her dark eyes"
    adj 1: (used especially of glances) directed to one side with or
           as if with doubt or suspicion or envy; "her eyes with
           their misted askance look"- Elizabeth Bowen; "sidelong
           glances" [syn: askance, askant, asquint, squint,
           squint-eyed, squinty, sidelong]

Moby Thesaurus II by Grady Ward, 1.0:

41 Moby Thesaurus words for "askance":
   aside, askant, askew, asquint, awry, broadside, broadside on, cam,
   captiously, censoriously, cock-a-hoop, cockeyed, crabwise,
   critically, crookedly, cynically, disapprovingly, distrustfully,
   doubtfully, doubtingly, edgeway, edgeways, edgewise, glancingly,
   laterad, laterally, on its side, on the beam, reproachfully,
   right and left, sideling, sidelong, sideward, sidewards, sideway,
   sideways, sidewise, sidling, skeptically, suspiciously,
   unfavorably