@freakboy3742 I'm not Slovene, but I *guess* it comes from somthing like ‘udarnik’, which means a shock worker, i.e. a very productive worker. In Soviet Union, udarniks were the people that would work more than needed for the benefit of society, socialism, and communism.

https://en.wikipedia.org/wiki/Udarnik

The word itself comes from the adjective ‘ударный’ (udarny) meaning ‘quickly, decisively acting’. Its ultimate root is the noun ‘удар’ — ‘shock’, ‘punch’, ‘strike’.