We Slavs, for the most part, call the Germans "Nemtsi", and this is directly related to our own ethnonym. During late Antiquity, when the tribes of Germanic and Slavic barbarians lived side by side, their level of development did not differ much. Life, habits, values - everything was about the same, the differences were only on a linguistic basis. So, this is how the "Slavs" (from the root "slovo" (word), that is, those who understand words) and the "Nemtsi" (from the root "nemoi" (numb), that is, those who do not speak understandable words) appeared.
I find it interesting how there are so many different words for “German” across different European languages from countries that are so geographically close to Germany. In English they’re “Germans,” in Spanish we call them “alemanes,” in French and Portuguese they also use words that are similar to “alemán” in Russian and Ukrainian they’re called “nemtsy” or “nemtsi” as you say, in Italian they’re called “Tedeschi,” the Germans refer to themselves as “Deutsch, and probably still some more languages have different words still. Why is this so? Usually most people from European countries are referred to similarly: the words for “Russians,” “Poles, “Frenchmen,” “Spaniards,” etc are generally the same across most languages I can think of, but Germany seems to be an exception. I don’t know, maybe I’m just retarded
Juan Butler
All I remember from history class is that north germanic tribes called slavs, Vender and that they lived in Vendland. Only the finnic language use the term today like Russia = Venäjä.