This is the 3817th most frequent Russian word.
marder
The word "marder" is not Russian; it is German for "marten," a small carnivorous mammal.
Here, 'мардер' (marder) refers to an animal, the marten, which is its biological context.
На дороге я увидел мардер, животное с пушистым хвостом.
On the road, I saw a marten, an animal with a fluffy tail.
In this sentence, 'Мардер' (Marder) refers to a specific type of military vehicle, a tank, thus indicating its historical and mechanical context.
В музее выставлен танк «Мардер», использовавшийся во второй мировой войне.
In the museum, the 'Marder' tank, which was used in World War II, is exhibited.
This usage reflects the metaphorical or legendary representation of 'marder' as a character in tales or stories.