The Collaborative International Dictionary of English v.0.48:

Otherwise \Oth"er*wise`\, adv. [Other + wise manner.]
   [1913 Webster]
   1. In a different manner; in another way, or in other ways;
      differently; contrarily. --Chaucer.
      [1913 Webster]

            Thy father was a worthy prince,
            And merited, alas! a better fate;
            But Heaven thought otherwise.         --Addison.
      [1913 Webster]

   2. In other respects.
      [1913 Webster]

            It is said, truly, that the best men otherwise are
            not always the best in regard of society. --Hooker.
      [1913 Webster]

   3. In different circumstances; under other conditions; as, I
      am engaged, otherwise I would accept.
      [1913 Webster]

   Note: Otherwise, like so and thus, may be used as a
         substitute for the opposite of a previous adjective,
         noun, etc.
         [1913 Webster]

               Let no man think me a fool; if otherwise, yet as
               a fool receive me.                 --2 Cor. xi.
                                                  16.
         [1913 Webster]

               Her eyebrows . . . rather full than otherwise.
                                                  --Fielding.
         [1913 Webster]

WordNet (r) 3.0 (2006):

otherwise
    adv 1: in other respects or ways; "he is otherwise normal"; "the
           funds are not otherwise available"; "an otherwise
           hopeless situation"
    2: in another and different manner; "very soon you will know
       differently"; "she thought otherwise"; "there is no way out
       other than the fire escape"; [syn: differently,
       otherwise, other than]
    adj 1: other than as supposed or expected; "the outcome was
           otherwise"

Moby Thesaurus II by Grady Ward, 1.0:

57 Moby Thesaurus words for "otherwise":
   a rebours, against the grain, alias, another, arsy-varsy,
   by contraries, contra, contrarily, contrariously, contrariwise,
   conversely, differently, disparate, dissimilar, distant, divergent,
   diverse, diversely, else, elsewise, if not, in another way,
   in flat opposition, in other respects, in other ways, inversely,
   just the opposite, nay rather, not that sort, not the same,
   not the type, of a sort, of another sort, of sorts,
   on the contrary, oppositely, or else, other, other than, peculiar,
   per contra, quite the contrary, rare, rather, special, sui generis,
   than, to the contrary, topsy-turvy, tout au contraire, unalike,
   unequal, unique, unlike, upside down, variously, vice versa



The Devil's Dictionary (1881-1906):

OTHERWISE, adv.  No better.