The Collaborative International Dictionary of English v.0.48:

Patient \Pa"tient\, n.
   1. One who, or that which, is passively affected; a passive
      recipient.
      [1913 Webster]

            Malice is a passion so impetuous and precipitate
            that it often involves the agent and the patient.
                                                  --Gov. of
                                                  Tongue.
      [1913 Webster]

   2. A person under medical or surgical treatment; --
      correlative to physician or nurse.
      [1913 Webster]

            Like a physician, . . . seeing his patient in a
            pestilent fever.                      --Sir P.
                                                  Sidney.
      [1913 Webster]

   In patient, a patient who receives lodging and food, as
      treatment, in a hospital or an infirmary.

   Out patient, one who receives advice and medicine, or
      treatment, from an infirmary.
      [1913 Webster]