Referential metonymy, e.g. ‘the moustache (= man with a moustache) sits down first’, appears early in L1 acquisition (Falkum, Recasens & Clark, 2017). Yet how does it emerge in pragmatically mature but linguistically developing adult L2 learners? We used one comprehension and two production tasks, based on Falkum and colleagues (2017), to investigate metonymy abilities in 34 Japanese adult learners of English as an additional language (EAL) and a control group of 31 native English speakers. We also examined how time constraints and exposure to examples of referential metonymy affected production. In the comprehension task, both EAL-learner and native-speaker participants chose metonymic readings at above chance levels. In both production tasks, all participants produced innovative metonyms. Additionally, the findings indicate that, in L2, exposure to examples dramatically increases metonymy production, while time pressure decreases it. The results suggest that participants can both comprehend and produce novel metonyms in L2, with a possible explicitness vs. production costs trade-off.