1) Hebrew surname 
Marshak, Marschak, Marczak (מרש`ק) is a Jewish (Ashkenazic) surname, which is an acronym from the Hebrew expression Morenu Rabbi Shmuel Kaidanover - `our teacher Rabbi Samuel Kaidanover`, after Aharon Shmuel ben Israel Kaidanover, a talmudic scholar and preacher from eastern Europe (Vilna, 1614 - Kraków, 1676). ...