Junker was originally the honorific of members of the higher edelfrei (immediate) nobility without or before the accolade. It evolved to a general denotation of a young or lesser noble, sometimes poor and politically insignificant (although this was not always the case, as in the prominent Swiss Meyer zum Pfeil family which used the honorific), understood as "country squire" (cf. Martin Luther's disguise as "Junker Jörg" at the Wartburg; he would later mock King Henry VIII of England as "Juncker Heintz"). As part of the nobility, many Junker families only had prepositions such as von or zu before their family names without further ranks. The abbreviation of Junker was Jkr., most often placed before the given name and titles, for example: Jkr. Heinrich von Hohenberg. The female equivalent Junkfrau (Jkfr.) was used only sporadically. In some cases, the honorific Jkr. was also used for Freiherren (Barons) and Grafen (Counts).
Junker was historically used across the German-speaking realm as a noble honorific, but since the 19th century, the designation became popularly associated with the landed nobility of the eastern part of the Kingdom of Prussia and its associated culture. The title today survives in its traditional meaning in the Netherlands and Belgium in the Dutch and Flemish form Jonkheer.
The term was also used in several countries in the title Kammerjunker, the German and Scandinavian (Danish, Norwegian and Swedish) equivalent of the French valet de chambre, a position usually given to young noble men in the service of a princely rank person at the court. A Kammerjunker was ranked below a chamberlain, but above a chamber page. Furthermore, the title has been used in military titles in the German and Scandinavian realm, such as Fahnenjunker and its Scandinavian equivalent fanejunker.
In Denmark, the term Junker connotes a young lord, originally the son of a duke or count in the Middle Ages, but also a term for a member of the privileged landowner class. Before 1375 the honorific was also suitable for Danish royal sons. It was also used in the title Kammerjunker within the royal household.
The word junker also can be used as a derisive term for a young man with arrogant and "classy" appearance.
- Duden; Meaning of Junker, in German. 
- Henry VIII: September 1540, 26-30', Letters and Papers, Foreign and Domestic, Henry VIII, Volume 16: 1540-1541 (1898), p. 51. URL: http://www.british-history.ac.uk/report.aspx?compid=76214 Date accessed: 10 June 2012