The Collaborative International Dictionary of English v.0.48:
Junker \Jun"ker\, n. [G. Cf. Yonker.] A young German noble or squire; esp., a member of the aristocratic party in Prussia. [1913 Webster]WordNet (r) 3.0 (2006):
Junker n 1: member of the Prussian aristocracy noted especially for militarism