Hospitaler \Hos"pi*tal*er\, n. [Written also {hospitaller}.] [F. hospitalier. See {Hospital}, and cf. {Hostler}.] 1. One residing in a hospital, for the purpose of receiving the poor, the sick, and strangers. 2. One of an order of knights who built a hospital at Jerusalem for pilgrims, A. D. 1042. They were called Knights of St. John of Jerusalem, and after the removal of the order to Malta, Knights of Malta.