Background Multimodal enrichment can enhance second language (L2) vocabulary learning, but most evidence comes from studies with extensive training; it is unclear whether similar benefits occur with limited exposure. Aims This study investigated how ten brief instances of gesture- and picture-based enrichment influenced adults’ learning and long-term retention of concrete and abstract L2 vocabulary. Sample Fifty-two German-speaking adults were recruited from teacher education programs at the University of Leipzig. Methods Using a fully within-participants design, each learner studied abstract and concrete L2 nouns under three conditions: listening only (no enrichment), listening while viewing related pictures (picture enrichment), and listening while viewing and performing related gestures (gesture enrichment). Each word was presented ten times across five training sessions. Word learning was assessed using free recall, L1–L2 translation, L2–L1 translation tasks at three retention intervals (day 8, month 2, and month 6). Results Both gesture and picture enrichment significantly improved learning of abstract words compared to no enrichment. For concrete words, performance did not differ across conditions. Gesture enrichment did not outperform picture enrichment at any time point. Memory performance declined over time, particularly for abstract words, while concrete word performance remained more stable. Conclusions Even brief exposure to gestural and pictorial enrichment can enhance the long-term retention of abstract L2 vocabulary. More extensive training may be required for gesture-based benefits to exceed those of picture enrichment. The findings establish boundary conditions for multimodal learning and inform both theoretical accounts of sensorimotor enrichment and practical approaches to language instruction.