chitchat vs discourse

chitchat and discourse both are nouns.

Word	Noun	Adjective	Verb	Adverb
chitchat	Yes	No	Yes	No
discourse	Yes	No	Yes	No

As verbs, discourse is a hypernym of chitchat; that is, discourse is a word with a broader meaning than chitchat:

Other hypernyms of chitchat include converse.

chitchat (noun)	discourse (noun)
light informal conversation for social occasions	an extended communication (often interactive) dealing with some particular topic
	extended verbal expression in speech or writing
	an address of a religious nature (usually delivered during a church service)

chitchat (verb)	discourse (verb)
talk socially without exchanging too much information	talk at length and formally about a topic
	carry on a conversation
	to consider or examine in speech or writing