Lecture
A lecture is when someone talks to a group of people about something interesting. It is like a lesson. At college or university, students go to lectures to learn things. The person who is teaching (talking to the group) is called the lecturer or sometimes professor. The lecturer may accept questions from the audience.
Sometimes we say that someone was "given a lecture". This means that he was told off for doing something wrong.
Lecture Media
Lecture at the Australian Defence Force Academy
Barbara McClintock delivers her Nobel lecture
Golan Levin lecturing using a projected slide
Rembrandt's The Anatomy Lecture of Dr. Nicolaes Tulp (1632)
William Hogarth's 1736 engraving, *Scholars at a Lecture
Civil lecture at Budapest Brain Bar
Professor of the Tampere University of Technology lecturing in 2007