The Collaborative International Dictionary of English v.0.48:

Notwithstanding \Not`with*stand"ing\, adv. or conj. [Originally
   the participle of withstand, with not prefixed.]
   Nevertheless; however; although; as, I shall go,
   notwithstanding it rains.
   [1913 Webster]

         I will surely rend the kingdom from thee, and will give
         it to thy servant. Notwithstanding, in thy days I will
         not do it.                               --1 Kings xi.
                                                  11, 12.
   [1913 Webster]

         They which honor the law as an image of the wisdom of
         God himself, are, notwithstanding, to know that the
         same had an end in Christ.               --Hooker.
   [1913 Webster]

         You did wisely and honestly too, notwithstanding
         She is the greatest beauty in the parish. --Fielding.
   [1913 Webster]

   Notwithstanding that, notwithstanding; although.
      [1913 Webster]

            These days were ages to him, notwithstanding that he
            was basking in the smiles of the pretty Mary. --W.
                                                  Irving.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Notwithstanding \Not`with*stand"ing\, prep.
   Without prevention, or obstruction from or by; in spite of.
   [1913 Webster]

         We gentil women bee
         Loth to displease any wight,
         Notwithstanding our great right.         --Chaucer's
                                                  Dream.
   [1913 Webster]

         Those on whom Christ bestowed miraculous cures were so
         transported that their gratitude made them,
         notwithstanding his prohibition, proclaim the wonders
         he had done.                             --Dr. H. More.
   [1913 Webster]

   Note: Notwithstanding was, by Johnson and Webster, viewed as
         a participle absolute, an English equivalent of the
         Latin non obstante. Its several meanings, either as
         preposition, adverb, or conjunction, are capable of
         being explained in this view. Later grammarians, while
         admitting that the word was originally a participle,
         and can be treated as such, prefer to class it as a
         preposition or disjunctive conjunction.
         [1913 Webster]

   Syn: In spite of; despite.

   Usage: Notwithstanding, In spite of, Despite. Of these,
          only notwithstanding can be used postpositively; as, I
          will go, the weather notwithstanding. With respect to
          meaning, these words and phrases are often
          interchanged, but there is a difference between them,
          chiefly in strength. Notwithstanding is the weaker
          term, and simply points to some obstacle that may
          exist; as, I shall go, notwithstanding the rain. In
          spite or despite of has reference primarily to active
          opposition to be encountered from others; as, "I'll
          be, in man's despite, a monarch; " "I'll keep mine
          own, despite of all the world." --Shak. Hence, these
          words, when applied to things, suppose greater
          opposition than notwithstanding. We should say. "He
          was thrust rudely out of doors in spite of his
          entreaties," rather than "notwithstanding". On the
          other hand, it would be more civil to say,
          "Notwithstanding all you have said, I must still
          differ with you."
          [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

notwithstanding
    adv 1: despite anything to the contrary (usually following a
           concession); "although I'm a little afraid, however I'd
           like to try it"; "while we disliked each other,
           nevertheless we agreed"; "he was a stern yet fair
           master"; "granted that it is dangerous, all the same I
           still want to go" [syn: however, nevertheless,
           withal, still, yet, all the same, even so,
           nonetheless, notwithstanding]

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "notwithstanding":
   after all, again, albeit, all the same, although, at all events,
   at any rate, but, despite, even, even so, for all that, howbeit,
   however, in any case, in any event, in spite, just the same,
   nevertheless, nonetheless, rather, regardless of, still, though,
   when, yet