The Collaborative International Dictionary of English v.0.48:

Obliquity \Ob*liq"ui*ty\, n.; pl. Obliquities. [L. obliquitas:
   cf. F. obliquit['e].]
   1. The condition of being oblique; deviation from a right
      line; deviation from parallelism or perpendicularity; the
      amount of such deviation; divergence; as, the obliquity of
      the ecliptic to the equator.
      [1913 Webster]

   2. Deviation from ordinary rules; irregularity; deviation
      from moral rectitude.
      [1913 Webster]

            To disobey [God] . . . imports a moral obliquity.
                                                  --South.
      [1913 Webster]

WordNet (r) 3.0 (2006):

obliquity
    n 1: the presentation during labor of the head of the fetus at
         an abnormal angle [syn: asynclitism, obliquity]
    2: the quality of being deceptive [syn: deceptiveness,
       obliquity]