The compilation of dictionaries to be used as special textbooks when learning a native or a non-native language is a special area of lexicography. Educational dictionaries have their own purpose, audience, and didactic focus. These determine the corpus of the language units described, the parameters of their lexicographic description, the content and structure of the dictionary text and entries, and the inclusion of special appendixes. Educational dictionaries also differ from reference dictionaries in their selectivity, which is expressed in orientation exclusively towards the literary norm, a purposeful and rigorous selection of language sources and language units, along with the parameters of their description and illustrative material. The specificity of educational dictionaries explains the limited scope of their use and the relatively small number of users. The sphere of modern communication is expanding and becoming more diverse. In the process of communication, a person is confronted with a large number of foreign words and expressions unknown to him, special names and terms from different areas of human knowledge, nominations, which are outside the literary language. A modern user is interested in more detailed information about language units: their origin and peculiar features, the way a word functions or expresses a concept in a language; the possibilities of using it in different communicative spheres, its morphological links, etc. The educational dictionaries cannot satisfy the overall need for such information. Therefore, it is necessary to refer to other types of dictionaries, in particular to reference dictionaries. Observations suggest that explanatory reference dictionaries have a certain educational potential and can be used as a supplement for educational dictionaries. Among their peculiar features it is necessary to note an extended vocabulary, which provides information on the language units that are not described in educational dictionaries; more detailed information on the form, content and usage of a lexical unit; the specifics of borrowed units’ functions in one’s native language and the source language, etc. The possible use of explanatory reference dictionaries for educational purposes substantiates the need to further improve contemporary dictionaries in a number of areas, including the update rate, the fullness, availability and convenience and information, selective use of the data contained in the dictionary, etc.