"young German noble," 1550s, from German Junker, from Old High German juncherro, literally "young lord," from junc "young" (see young (adj.)) + herro "lord" (see Herr). Pejorative sense of "reactionary younger member of the Prussian aristocracy" (1865) is from Bismarck's domestic policy. Related: Junkerism. Meaning "drug addict" is from 1922; that of "old worn-out automobile" is from 1969, both from junk (n.1).