(a) In many verbs, verbal nouns, and verbal adjs. taken either from L or OF, dis- clearly has adversative or privitive force, as in disal(l)ouen, disavauntage, disavouen, discomfort, disconsolat, disfiguren, displesen, dispreven, disseisen vs. al(l)ouen, avauntage, comfort, plesen, etc.; (b) hence it is used with this meaning to form such derivatives as disaperen, disencres, disfraunchisen in ME (some of these may, however, be AF creations).

In other words taken from L or OF the force of dis- is vague from the ME point of view, since the simplex is either not current or has different meanings, as in discret, discussen, disport, disposen, disputacioun, dissencioun. It has, or may have, completive or intensive force in dismaten, disseveren, dissolut, etc.