The Collaborative International Dictionary of English v.0.48:

Severity \Se*ver"i*ty\, n.; pl. Severities. [L. severitas: cf.
   F. s['e]v['e]rit['e].]
   The quality or state of being severe. Specifically:
   [1913 Webster]
   (a) Gravity or austerity; extreme strictness; rigor;
       harshness; as, the severity of a reprimand or a reproof;
       severity of discipline or government; severity of
       penalties. "Strict age, and sour severity." --Milton.
       [1913 Webster]
   (b) The quality or power of distressing or paining; extreme
       degree; extremity; intensity; inclemency; as, the
       severity of pain or anguish; the severity of cold or
       heat; the severity of the winter.
       [1913 Webster]
   (c) Harshness; cruel treatment; sharpness of punishment; as,
       severity practiced on prisoners of war.
       [1913 Webster]
   (d) Exactness; rigorousness; strictness; as, the severity of
       a test.
       [1913 Webster]

             Confining myself to the severity of truth.
                                                  --Dryden.
       [1913 Webster]