Evolution and Trends in EFL/ESL Vocabulary Development in Higher Education: Bibliometric and Content Analysis (1984–2024)

The current study presents a systematic bibliometric review on English as a Foreign Language (EFL) and English as a Second Language (ESL) vocabulary research in higher education from 1984 to 2024. Using 601 Scopus-indexed articles as a dataset, the research analyses trends in publications, research collaboration networks, leading authors, prominent journals, main thematic directions and emerging research gaps. By employing descriptive statistics, co-word analysis, and bibliographic coupling, the study systematically maps the intellectual and structural landscape of the field. The findings indicate a gradual increase in publication trends over the last two decades, with Iran, China, and the United States being the most productive and significant contributors to co-authorship. Key research topics include receptive versus productive vocabulary knowledge, incidental vocabulary learning, mobile-assisted language learning, and data-driven learning. Although there is an increasing interest in technology-assisted vocabulary learning, the study indicates a lack of research into the sustainability, scalability, and contextual adaptability of such innovations. The findings underscore the importance of interdisciplinary work, culturally responsive pedagogy, and longitudinal empirical research to inform future studies. Combining a historical overview, discussion of key authors, and directions in the field, it provides rich material to advance knowledge on and teaching of vocabulary development from an EFL/ESL perspective at the university level.