dux

n. (in Britain and Scotland) student who is academically first in a class or school, student whose academic achievements are the highest in a specific subject or in a class or school

The DUX-53 and DUX-59 were submachine guns designed at the Oviedo Arsenal in Spain. They were based directly on the design of the Finnish 9mm Model 44 submachine gun, which in turn was based on the Soviet PPS-43. A large number of these weapons were produced for the West German Border Police, and was later licensed to be produced by Anschütz and Mauser until the mid 1950s.
See more at Wikipedia.org...

For the town in the Czech Republic, sometimes known by its German name Dux, see Duchcov. Dux (plural: duces) is Latin for leader (from the verb ducere, 'to lead') and could refer to anyone who commanded troops, such as tribal leaders.
See more at Wikipedia.org...

n. dux

n. doge

(n.)
The scholastic name for the theme or subject of a fugue, the answer being called the comes, or companion.