Content and language integrated learning (CLIL), an educational approach using a foreign language to teach non-language subjects, has been consistently gaining in popularity. Despite an increasing research base suggesting its benefits for general language proficiency, the contribution made to learning and using subject-specific target language elements is largely under-researched. This paper addresses one aspect of this, i.e. students’ use of subject-specific vocabulary in CLIL classroom communication. It proposes a holistic model for identifying both single and multi-word lexical units specific to the school subject in oral classroom data, integrating corpus-linguistic and qualitative data analysis. The method is trialled using a data set of 16 hours of secondary-school CLIL classroom data within the subject of European economics and politics in Year 12. Findings show that a holistic definition of subject-specific vocabulary is vital, and that the model constitutes an adequate and flexible tool for specifying CLIL terminology in oral classroom discourse.