The Collaborative International Dictionary of English v.0.48:

Oracular \O*rac"u*lar\, a. [L. oracularius. See Oracle.]
   1. Of or pertaining to an oracle; uttering oracles;
      forecasting the future; as, an oracular tongue.
      [1913 Webster]

   2. Resembling an oracle in some way, as in solemnity, wisdom,
      authority, obscurity, ambiguity, dogmatism.
      [1913 Webster]

            They have something venerable and oracular in that
            unadorned gravity and shortness in the expression.
                                                  --Pope.
      [1913 Webster] -- O*rac"u*lar*ly, adv. --
      O*rac"u*lar*ness, n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

oracular
    adj 1: of or relating to an oracle; "able by oracular means to
           expose a witch"
    2: obscurely prophetic; "Delphic pronouncements"; "an oracular
       message" [syn: Delphic, oracular]
    3: resembling an oracle in obscurity of thought; "the oracular
       sayings of Victorian poets"; "so enigmatic that priests might
       have to clarify it"; "an enigmatic smile" [syn: enigmatic,
       oracular]

Moby Thesaurus II by Grady Ward, 1.0:

45 Moby Thesaurus words for "oracular":
   apocalyptic, augural, auguring, bigoted, conceited, divinatory,
   doctrinaire, doctrinarian, dogmatic, dogmatizing, fatidic,
   forecasting, foreseeing, foretelling, forewarning, fortunetelling,
   haruspical, mantic, opinionated, opinionative, opinioned,
   peremptory, pontifical, positive, positivistic, predictional,
   predictive, predictory, prefigurative, prefiguring, presageful,
   presaging, presignificative, presignifying, prognostic,
   prognosticative, pronunciative, prophetic, self-opinionated,
   self-opinioned, sibyllic, sibylline, vaticinal, vaticinatory,
   weather-wise