Language instructors play a decisive role in adult language learners' learning and retention of vocabulary through planning, selection, and teaching of vocabulary and strategies. However, some professional language schools lack extensive teacher-training programs that prepare instructors with the skills required to select and teach vocabulary, which results in a gap in practice. The purpose of this study was to explore teacher-related factors in beyond Interagency Language Roundtable (ILR) Level 2 vocabulary instruction to adults in a classroom setting in intensive language-training programs. The conceptual framework consisted of the theory of noticing hypothesis, synformy, and the comprehensible input hypothesis. Research questions addressed instructors' experiences when teaching vocabulary and synforms, the training they received on how to teach vocabulary, and the resources they need. Data were collected through semistructured interviews with 9 language instructors of less-commonly taught languages. Data were analyzed using an open-coding strategy. Results indicated participants were uncertain about their roles in teaching and selecting vocabulary and about the use of strategies and approximate number of words and kinds of words that students require to achieve general proficiency (ILR Level 3). Participants reported they had no systematic approach to teaching vocabulary or synforms. Participants also expressed a desire to receive training on vocabulary learning strategies, evidence-based best practices in teaching vocabulary, and facilitating vocabulary retention. Findings may be used to guide directors of intensive language programs in developing systematic approaches to selecting and teaching vocabulary.