Talk
Part of speech: noun
Definition: A conversation. What is being said about a subject of interest. A lecture.
Part of speech: verb
Definition: To communicate, usually by means of speech. To discuss.
Example sentence: Sometimes I wish that I was the weather, you'd bring me up in conversation forever. And when it rained, I'd be the talk of the day.
Lecture
Part of speech: noun
Definition: A spoken lesson or exposition, usually delivered to group.
Part of speech: verb
Definition: To teach, by giving a speech on a given topic.To berate, to scold.
Example sentence: Professors simply can't discuss a thing. Habit compels them to deliver a lecture.