Learning from texts requires reflection on how far one has mastered the material. Learners use such metacognitive processes to decide whether to engage in deeper learning activities or not. This article examines how the lexical surface of specialist concepts influences their mental representation. Lexical encodings that are the concise wordings of a concept (e.g., tension headache or migraine for specific types of headache) provide immediate access to the underlying content. To understand learning contents appropriately, learners have to work on such lexical covers to gain insight into the underlying semantic meaning. It was assumed that a technical term's origin (either German or classical Latin/Greek) is used systematically as a hint for further elaboration. 41 college students rated the difficulty, familiarity, competence, accessibility, and their knowledge of 17 German-language (GL) terms and their classical language (CL) synonyms. The influence of word frequency was controlled. As expected, results showed that GL terms were perceived to be less difficult than CL terms. Consequently, comprehension of these terms was rated more highly. Analyses of how lexical encoding influenced accuracy of participants' comprehension judgments showed that participants' comprehension ratings were less accurate for GL terms. Theoretical and practical implications for learning from written information are discussed.