A lecturer.
to be polite when Walter Cunningham is dining at their house and not mock his ways
The teacher gave a lecture about the importance of agriculture.
Jody loves to lecture her friends on how brilliant WikiAnswers is.
how the fairness doctrine is not fair. ( if there is 1 hour of republican talk on the radio there must be 1 hour of democratic talk and 80% of people want republican so it doesn't make sense!)