demonstrably

adv

1. In such a manner that is capable of being demonstrated, shown, or proved (without doubt).

   “The country has become demonstrably less safe under his leadership.”

   “Hence it followeth demonstrably, if our refusall to receiue Maister Blackwell to our Arch-priest, did, or could any way possibly make vs schismaticks, that the only and principall cause of such our refusall, was, and of all necessitie must needes haue bin, for that the Pope (note our words) or the Cardinall by his commission, had (instituting the subordination) appointed him for our Superior […]”

   “Which (besides, that it would justifie the Socinian, in telling the World, That they have been a long Time troubled with a needless sort of Men called Preachers or Ministers) is most demonstrably false, there being some Thousands in the World, that can Discourse well in Company, and many Lawyers that can Plead very well at a Bar;”