In Russian language, the prefixal nonsuffixal nouns account for roughly two percent. In the ancient texts, many of the nouns were calques from Greek. Over time, the methods of their formation and the scope of their use have expanded. Recently, the use of this kind of words in the colloquial speech has grown. Words, which were created through forward-formation, such as бег > забег, блеск > отблеск, свет > отсвет, внук > правнук, match Vinokur's criterion, according to which, the derivatum is more complex than the generating word. It can be stimulated by calques of the foreign words. We suggest explaining cases of the violation of this criterion not by zero suffixation, but by back-formation, according to James Murray, N. Shanskii and G. Nikolayev, for example, призывать > призыв, спасть > спад, обмануть > обман, вгибать > вгиб, вводить > ввод, отрывать > отрыв. These derivative nouns always appear later than their generating verbs. Back‑formation develops as a result of redefining derivational connections and creating back-formational interrelationship, which occurs due to the enhanced relevance of the verbal predicative center of a sentence.