The Collaborative International Dictionary of English v.0.48:

Feverish \Fe"ver*ish\, a.
   1. Having a fever; suffering from, or affected with, a
      moderate degree of fever; showing increased heat and
      thirst; as, the patient is feverish.
      [1913 Webster]

   2. Indicating, or pertaining to, fever; characteristic of a
      fever; as, feverish symptoms.
      [1913 Webster]

   3. Hot; sultry. "The feverish north." --Dryden.
      [1913 Webster]

   4. Disordered as by fever; excited; restless; as, the
      feverish condition of the commercial world.

   Syn: fevered.
        [1913 Webster]

              Strive to keep up a frail and feverish being.
                                                  --Milton.
        -- Fe"ver*ish*ly, adv. -- Fe"ver*ish*ness, n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

feverishly
    adv 1: in a feverish manner; "she worked feverishly"