The paper represents a part of an extensive study devoted to the issues of lexical meaning formal representation in OWL 2 DL notation. Both theoretical and methodological aspects of lexical meaning formalization within the framework of an ontology are observed in the paper. Model-theoretic semantics paradigm and Kripke model are considered to form a theoretical background for formalization of lexical meaning, whereas the NL-DL definition transformation method is investigated as a method designed to provide us with acceptable formal definitions in OWL 2 DL notation with natural language definitions given at the input. A brief critical study of the method has allowed to reveal particular problematic cases of the method application, which arise due to syntactic peculiarities of natural language definitions given at the input.