discourse

extended verbal expression in speech or writing

an address of a religious nature (usually delivered during a church service)

an extended communication (often interactive) dealing with some particular topic; "the book contains an excellent discussion of modal logic"; "his treatment of the race question is badly biased"

to consider or examine in speech or writing; "The author talks about the different aspects of this question"; "The class discussed Dante's `Inferno'"

carry on a conversation

talk at length and formally about a topic; "The speaker dissertated about the social politics in 18th century England"