The Collaborative International Dictionary of English v.0.48:

Critically \Crit"ic*al*ly\, adv.
   1. In a critical manner; with nice discernment; accurately;
      exactly.
      [1913 Webster]

            Critically to discern good writers from bad.
                                                  --Dryden.
      [1913 Webster]

   2. At a crisis; at a critical time; in a situation, place, or
      condition of decisive consequence; as, a fortification
      critically situated.
      [1913 Webster]

            Coming critically the night before the session.
                                                  --Bp. Burnet.
      [1913 Webster]

WordNet (r) 3.0 (2006):

critically
    adv 1: in a critical manner; "this must be examined critically"
           [ant: uncritically]