The present study investigated the subjective lexical characteristics of words stemming from a medical context by comparing estimations of the target population (age range = 46–89) and of doctors. A total of 58 members of the target population and 22 oncologists completed measures of subjective frequency and emotional valence for words previously collected in interviews of announcement of cancer diagnosis. The members of the target population also completed tests of word definitions, without and within context. As expected, most of the words were rated less familiar, more negative and as generating more intense emotions to the target population than to the doctors. Moreover, only a few words were correctly defined by the target population. Adding a context helped the participants to define most of the words correctly. Importantly, we identified words that were rated familiar by the patients although they did not know their exact meaning. Overall, these results highlight the importance of taking into account the subjective lexical characteristics of words used in specific contexts.