Cognitive semiotics focuses on the study of sign formations in general and linguistic signs in particular, but not only those that are the holders of contemporary reflection of the phenomena of the surrounding world. The etymon belongs to the diachronically determined sign formations. On the one hand, it is a material reflection of the results of knowledge (cognition) by the carriers of the primordial consciousness of certain fragments of the past reality, i.e. the sign-archetype. On the other hand, its standard form (phonomorphological form) represented in the etymological sources. Indeed, the cognitive-semiotic reconstruction of etymon takes place on the basis of the sensation of the present time with the help of such an imagination (scientific etymological experience) of the researcher. It enables to reveal the inner idea of the standard state, i.e. the archetype (to comprehend its cognitive essence as a sign of extra-native nature). Accordingly, the etymologist deals with the genetic material, the totality of which contributes to the formation of his / her ideas about the primordial sign nature of the restored formal form, which correlates with the concrete meaning (s). Etymon is a unit of deep diachronic level. It acts as a representation of the primordial status of a particular unit of analysis or a group of languages and it can be represented as proto-root, proto-morpheme, as well as individual morphemes and even phonemes. It depends on the tasks that the researcher poses, in particular the etymological depth to which he / she plans or may come closer. But in order to determine the initial form of different etymological depth it is necessary to rely on the semantic transformations involved in the etymological analysis of word-forming derivatives. The latter reflect the symbolic understanding of the restored form within a broad cultural context (the language family of a deeper diachrony) and the narrower primordial language for various groups of related languages. The reconstruction of etymon as a cognitive-semiotic formation of various chronological depths shows which were the primordial archetypal representations of carriers of different languages about the surrounding world, culture, life, etc. Consequently, the modern cognitive-oriented linguistic and comparative studios are not limited to phonetic laws aimed at proving coincidences only of the "material", sound side of the history of the word. They also involve various tools for the reconstruction of the meaning of the word, which preserves the deep and secret meanings, the true understanding of each language. Thanks to modern developments in the theory of cognitive semantics, which rely on semiotic-onomasiological work, the implementation of the semantic reconstruction of the standardised classes becomes a reality and reduces sharp discussions around this problem.