Significatio and significatus as terms denoting diathesis in the ancient Roman grammar

The term significatio, which refers to the category of diathesis (voice), entered the terminological apparatus of Roman grammarians no earlier than the end of the second century AD, but rather it happened only during the next century. However, the basis for the use of that term was laid by Valerius Probus no later than the beginning of the second century AD. If not Cominian, then Diomedes was the grammarian who in the first half of the fourth century AD finally established the use of the term significatio for verbal voice due to the insufficiency of the old term genus verborum. The use of the term significatio has issued from reasoning about the complex relation between semantics and morphology. The relatively rare term signifi catus served to highlight those cases where this relation was particularly intricate or subject to debate. Tracing the application of the latter term, as well as the analogous Greek term τὸ σημαινόμενον, it is possible to establish a certain continuity in the works of grammarians. Examples concerning verbal voice were, by all evidence, used already by the Stoic Posidonius to illustrate the complexity of the semantics–morphology relation. Valerius Probus, apparently, assimilated the corresponding Greek tradition through acquaintance with the works of the grammarian Habron and applied
it to his theory of verb forms.