prelection
/ˈprɛlkʃən/Definitions
1. noun
a preliminary lecture or discourse, especially one given to students before they begin their formal study of a subject
“The professor’s prelection on the history of the novel set the tone for the rest of the semester.”
2. noun
a preliminary exposition or introduction to a subject
“The prelection on the course syllabus provided a useful overview of the material to be covered.”