This article examines the characteristics of developing lexical competence among university students while studying the Ukrainian language for professional purposes, specifically the restrictions on the use of slang terms; it characterizes the concept of slang and its status within the system of non-literary vocabulary; identifies the main sources of student slang; classifies common slang units in contemporary Ukrainian youth speech; and analyzes their functions in communication. The didactic essence of the issue at hand in the context of teaching the Ukrainian language for professional purposes is demonstrated: it is emphasized that efforts to reduce the use of slang terms contribute to the formation of the linguistic culture of future specialists and their professional orientation. It has been established that slang not only reflects the specifics of the younger generation’s communication, its cultural orientations, social practices, and the influence of the globalized information space, but also pollutes professional speech. The modern Ukrainian language is undergoing active development, driven by both internal linguistic processes and the influence of social, cultural, and technological factors. One of the most dynamic layers of the lexicon is slang, which is particularly prevalent in the linguistic environment of young students. Youth slang reflects the specific nature of the younger generation’s communication, its cultural references, social practices, and the influence of the globalized information space. The relevance of this study stems from the fact that in the 21st century, youth and student speech is undergoing significant changes under the influence of digital technologies, social media, and intercultural communication. These processes contribute to the active borrowing of foreign-language vocabulary, primarily from English, as well as the formation of new slang units that spread rapidly in the communicative space. In this regard, the issue of slang as a linguistic phenomenon has attracted significant attention from researchers and has been extensively addressed in both domestic and foreign linguistics. The issue of contemporary youth slang in Ukrainian speech is thoroughly examined in the work by V. Zayets, O. Stepanenko, and Y. Stepchuk, where it is characterized as an open and dynamic system that actively responds to changes in society and the digital environment. The researchers propose a thematic classification of slang units and emphasize their expressiveness. At the same time, K. A. Brovko focuses on the mechanisms of online slang formation, highlighting such productive methods as abbreviation, truncation, word formation, and semantic shifts, which are also characteristic of Ukrainian youth speech. Despite linguists’ significant interest in the issue of non-literary vocabulary, the question of the functioning and classification of contemporary student slang in the Ukrainian language requires further study. Of particular relevance is the analysis of the sources of slang vocabulary formation, its structural features, and its role in shaping the linguistic identity of young people. Youth slang is an integral and one of the most dynamic components of modern Ukrainian speech, reflecting the active sociocultural and technological transformations of society. It is shaped by both intralinguistic processes (word formation, semantic reinterpretation, and linguistic play) and external factors, primarily globalization and the English-language information space. In formal business style, its use is undesirable and limited, but possible under certain conditions. The analysis conducted has shown that slang is not a homogeneous phenomenon and can be classified according to social, communicative, functional, and genetic criteria. This allows us to view it as a complex system encompassing professional, age-based, subcultural, and marginal varieties, as well as one that functions in various communicative environments – from everyday communication to the digital space. It has been demonstrated that youth slang performs a number of important functions: expressive, identificatory, speech-economizing, conspiratorial, and creative. It is precisely through these functions that it ensures not only effective communication but also the formation of group identity, serving as a means of self-expression for young people. A characteristic feature of slang is its instability and rapid changeability: some units disappear or transition into general vocabulary, losing their stylistic distinctiveness. This confirms the openness of the language system and its ability to adapt to new conditions. Thus, youth slang should be viewed not as a deviation from the linguistic norm, but as a natural manifestation of language development that reflects the current communication needs and cultural orientations of modern society.