Observable

observable
    adj 1: capable of being seen or noticed; "a discernible change
           in attitude"; "a clearly evident erasure in the
           manuscript"; "an observable change in behavior" [syn:
           {discernible}, {evident}, {observable}]
    

Observable \Ob*serv"a*ble\, a. [L. observabilis: cf. F.
   observable.]
   1. Capable of being observed; discernible; noticeable. --Sir.
      T. Browne.
      [1913 Webster]

            The difference is sufficiently observable.
                                                  --Southey.
      [1913 Webster]

   2. Worthy of being observed; important enough to be noted or
      celebrated; as, an observable anniversary.
      [PJC]

   3. Noteworthy; remarkable.
      [PJC] -- {Ob*serv"a*ble*ness}, n. -- {Ob*serv"a*bly}, adv.
      [1913 Webster]
    

62 Moby Thesaurus words for "observable":
      apparent, appreciable, beholdable, clear, clear as crystal,
      crystal-clear, detectable, discernible, disclosed, distinct,
      evident, explicit, exposed, exposed to view, express, hanging out,
      in evidence, in full view, in plain sight, in view, indisputable,
      indubitable, insight, manifest, memorable, naked, notable,
      noticeable, obvious, open, open to view, open-and-shut,
      outcropping, palpable, patent, perceivable, perceptible,
      perspicuous, plain, plain as day, recognizable, red-letter,
      revealed, rubric, seeable, self-evident, self-explaining,
      self-explanatory, sensible, showing, tangible, to be seen,
      transparent, unclouded, unconcealed, undisguised, unhidden,
      unmistakable, viewable, visible, visual, witnessable