[1] : The Collaborative International Dictionary of English v.0.48

probable \prob"able\, a. l. probabilis, fr. probare to try,
   approve, prove: cf. f. probable. see prove, and cf.
   provable.
   1913 webster
   1. capable of being proved. obs.
      1913 webster

   2. having more evidence for than against; supported by
      evidence which inclines the mind to believe, but leaves
      some room for doubt; likely.
      1913 webster

            that is accounted probable which has better
            arguments producible for it than can be brought
            against it.                           --south.
      1913 webster

            i do not say that the principles of religion are
            merely probable; i have before asserted them to be
            morally certain.                      --bp. wilkins.
      1913 webster

   3. rendering probable; supporting, or giving ground for,
      belief, but not demonstrating; as, probable evidence;
      probable presumption. --blackstone.
      1913 webster

   probable cause law, a reasonable ground of presumption
      that a charge is, or my be, well founded.

   probable error of an observation, or of the mean of a
      number, that within which, taken positively and
      negatively, there is an even chance that the real error
      shall lie. thus, if 3sec is the probable error in a
      given case, the chances that the real error is greater
      than 3sec are equal to the chances that it is less. the
      probable error is computed from the observations made, and
      is used to express their degree of accuracy.

   the probable, that which is within the bounds of
      probability; that which is not unnatural or preternatural;
      -- opposed to the marvelous.
      1913 webster
see also:
prove provable probable cause probable error the probable 

[2] : WordNet (r) 2.0

probable cause
     n : law evidence sufficient to warrant an arrest or search and
         seizure; "a magistrate determined that there was probable
         cause to search the house"

Probable Cause >> P Words
Probable Cause, definition of term: Probable Cause
probable+cause_pag1.html

Probable >> P Words
Probable, definition of term: Probable
probable_pag1.html

Cause >> C Words
Cause, definition of term: Cause
cause_pag1.html

Cause Harm >> C Words
Cause Harm, definition of term: Cause Harm
cause+harm_pag1.html

Cause Celebre >> C Words
Cause Celebre, definition of term: Cause Celebre
cause+celebre_pag1.html

Proximate Cause >> P Words
Proximate Cause, definition of term: Proximate Cause
proximate+cause_pag1.html

Efficient Cause >> E Words
Efficient Cause, definition of term: Efficient Cause
efficient+cause_pag1.html