Wiktionary
prolative
a. 1 (context obsolete English) uttered 2 (context grammar English) extending or completing a predication n. (context grammar English) the prolative case
Wikipedia
Usage examples of "prolative".
He had suffered much from his own lack of education and he wished these boys to be literate creatures, to whom the difference between an ablative absolute and a prolative infinitive was as evident as that between a ship and a brig.