The Collaborative International Dictionary of English v.0.48:

Obvious \Ob"vi*ous\, a. [L. obvius; ob (see Ob-) + via way.
   See Voyage.]
   1. Opposing; fronting. [Obs.]
      [1913 Webster]

            To the evil turn
            My obvious breast.                    --Milton.
      [1913 Webster]

   2. Exposed; subject; open; liable. [Obs.] "Obvious to
      dispute." --Milton.
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   3. Easily discovered, seen, or understood; readily perceived
      by the eye or the intellect; plain; evident; apparent; as,
      an obvious meaning; an obvious remark.
      [1913 Webster]

            Apart and easy to be known they lie,
            Amidst the heap, and obvious to the eye. --Pope.
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   Syn: Plain; clear; evident. See Manifest.
        [1913 Webster] -- Ob"vi*ous*ly, adv. --
        Ob"vi*ous-ness, n.
        [1913 Webster] Obvolute

WordNet (r) 3.0 (2006):

obviously
    adv 1: unmistakably (`plain' is often used informally for
           `plainly'); "the answer is obviously wrong"; "she was in
           bed and evidently in great pain"; "he was manifestly too
           important to leave off the guest list"; "it is all
           patently nonsense"; "she has apparently been living here
           for some time"; "I thought he owned the property, but
           apparently not"; "You are plainly wrong"; "he is plain
           stubborn" [syn: obviously, evidently, manifestly,
           patently, apparently, plainly, plain]

Moby Thesaurus II by Grady Ward, 1.0:

62 Moby Thesaurus words for "obviously":
   absolutely, actually, apparently, assuredly, certainly, clearly,
   conspicuously, de facto, decidedly, definitely, demonstrably,
   discernibly, distinctly, doubtlessly, evidently, explicitly,
   expressly, for a certainty, for real, genuinely, glaringly,
   in actuality, in all conscience, in effect, in fact, in reality,
   indeed, indubitably, manifestly, markedly, noticeably, observably,
   of course, palpably, patently, perceivably, perceptibly, plainly,
   positively, prominently, pronouncedly, quite, really, recognizably,
   seeably, sensibly, seriously, simply, staringly, starkly, truly,
   unambiguously, unconcealedly, undeniable, undeniably,
   undisguisedly, unmistakably, verily, veritably, visibly,
   with clarity, without doubt