The ending "rowitz" means "Son of" "Leiser" is the Yidish form of Elijah, or Elias or Elija in German. So in Hebrew it should be translated to: Ben Eliyahu In German: Eliassohn In English: Son of Elija ? (any suggestions?) Elija: Prophet of the bible, name is Hebrew and means "My god is YHWH" (Yahweh - but Jewish religious do not speak out the name).
The writing "witz" is the German form - short migration from Lithuania to Prussia across the border - in Prussia the Jews were very German - and gave later very German sounding names to their children (Generations from Immigrant to my father: First "Judel" than "Hirsch" "Max" last (*1914) "Hans Georg".
In Polish it would be the ending "wicz", I belive.