Source : Webster's Revised Unabridged Dictionary (1913)

Grievous \Griev"ous\, a. [OF. grevous, grevos, LL. gravosus. See
   {Grief}.]
   1. Causing grief or sorrow; painful; afflictive; hard to
      bear; offensive; harmful.

            The famine was grievous in the land.  --Gen. xii.
                                                  10.

            The thing was very grievous in Abraham's sight.
                                                  --Gen. xxi.
                                                  11.

   2. Characterized by great atrocity; heinous; aggravated;
      flagitious; as, a grievous sin. --Gen. xviii. 20.

   3. Full of, or expressing, grief; showing great sorrow or
      affliction; as, a grievous cry. -- {Griev"ous*ly}, adv. --
      {Griev"ous*ness}, n.

Source : WordNet®

grievously
     adv : in a grievous manner; "the resolute but unbroken Germany,
           grievously wounded but far from destruction, was able
           to lay the firm foundations for military revival"