Source : Webster's Revised Unabridged Dictionary (1913)

Inpatient \In"pa`tient\, n.
   A patient who receives lodging and food, as well as
   treatment, in a hospital or an infirmary; -- distinguished
   from {outpatient}.

Source : WordNet®

inpatient
     n : a patient who is residing in the hospital where he is being
         treated [syn: {inmate}] [ant: {outpatient}]