In posse

from The Collaborative International Dictionary of English v.0.48

In posse \In` pos"se\ [L.]
   In possibility; possible, although not yet in existence or
   come to pass; -- contradistinguished from {in esse}.
   [1913 Webster]

from The Collaborative International Dictionary of English v.0.48

Posse \Pos"se\, n.
   See {Posse comitatus}.
   [1913 Webster]

   {In posse}. See {In posse} in the Vocabulary.
      [1913 Webster]

from Bouvier's Law Dictionary, Revised 6th Ed (1856)

IN POSSE. In possibility; not in actual existence; used in contradistinction 
to in esse.

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