Point of issue in the article are aspects and parameters of comparative studies of different type of words' nests (word-formative, morphemic, lexico-semantic) within the framework of one or more languages. Most of the words' nests in categorization the world and the system organization of a lexicon of Slavic languages are marked. The first part of article presents studies of words' nests in the Ukrainian linguistics. The second part of the article is devoted to the comparative analysis of formal and semantic structure of words' nests of the Ukrainian verb 'pisati' and the Polish verb 'pisac'. The lexical complexes formed by these words' nests also serve as an object of analysis.