discourse vs argue

discourse is a noun but argue is not a noun.

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

As verbs, argue is a hyponym of discourse; that is, argue is a word with a more specific, narrower meaning than discourse:

discourse (noun)	argue (noun)
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)

discourse (verb)	argue (verb)
talk at length and formally about a topic	have an argument about something
carry on a conversation	give evidence of
to consider or examine in speech or writing	present reasons and arguments