A Discourse (n.) is an exacting type of communication that removes communication from context, generalizes principles that ought to be agreed upon, and abstracts what ideas of sort may be rationally accepted by adducing the best reasons.
Discourse (n.) is communication (or speech) in which we attempt to reestablish a state of communication (where information is exchange) where validity claims have become problematized and have become an explicit topics of discussion, but no information is exchanged.
Discourse (n.) is, for Habermas, the level of argumentation that can lead to a 'good consensus', that is, a rationally motivated one, freed from distortions of power.
A Discourse (n.) is speech freed from power, which is to say, speech that is under a universalized principle.
A Discourse (n.) allows only one kind of pressure, the unforced force of the better argument, so a norm counts as valid only if everyone it touches could agree to it as a participant.