old prussian: a dead language of the (non-German) Prussians (extinct after 1700); thought to belong to the Baltic branch of Indo-European
baltic: a branch of the Indo-European family of languages related to the Slavonic languages; Baltic languages have preserved many archaic features that are believed to have existed in Proto-Indo European
doorway: the entrance (the space in a wall) through which you enter or leave a room or building; the space that a door can close